UJ 答题框架打印

The Four-Step Inquiry for Unjust Enrichment Shanghai Tongji
不当得利的四步调查框架上海同济

例句：P has a potential claim in the law of unjust enrichment against the D for the restitution of HKD paid. To advise P, this answer will apply the four-step framework for unjust enrichment established in Hong Kong by Shanghai Tongji. The central issues will be (具体类别)
例句：P 对 D 因支付的港币有潜在的不当得利返还请求权。为向 P 提供建议，本答案将适用上海同济在香港确立的不当得利四步框架。核心问题将是（具体类别）

1. Was the defendant enriched?
1. 被告是否获得了利益？
2. Was the enrichment at the plaintiff's expense?
2. 该利益是否以原告为代价？
3. Was the enrichment unjust?
3. 该利益是否不当？
4. Are any of the defences applicable?
4. 是否适用任何抗辩？

例句: The foundational steps of unjust enrichment from Shanghai Tongji are that B must have been enriched at A's expense, and the enrichment must be unjust. B was enriched by the receipt of cleaning services, and this was at A's expense, who provided the labour. The unjust factor from A's perspective is his mistake in believing that B, as a resident, wanted his car cleaned. The central legal battleground, therefore, will be the valuation of this enrichment and whether B has a valid defence.
例句：上海同济关于不当得利的基本步骤是，B 必须是在 A 的费用下获得利益，且该利益必须是不当的。B 通过接受清洁服务而获益，而这正是由提供劳务的 A 承担费用。从 A 的角度看，不当因素是他错误地认为作为居民的 B 希望清洁他的汽车。因此，核心法律争议将是该利益的估值以及 B 是否有有效抗辩。

Step 1: Was the Defendant Enriched? (Enrichment) (C2)
步骤 1：被告是否获得利益？（利益）（C2）

Definition and Types of Benefits
利益的定义及类型

Positive benefits: An increase in the defendant's assets, most commonly money and services. It also includes goods, title to land, etc.
积极利益：被告资产的增加，最常见的是金钱和服务。还包括货物、土地所有权等。

例句: Enrichment is defined as receiving something of value. The D received HKD in money from P. Money is a universal medium of exchange (BP Exploration). Its receipt constitutes an incontrovertible benefit. The D was therefore clearly enriched.
例句：利益被定义为获得有价值的东西。被告从原告处收到了港币。金钱是一种通用的交换媒介（BP Exploration 案）。其接收构成了无可争辩的利益。因此，被告显然获得了利益。

Negative benefits: The saving of an expense or the discharge of a debt.
消极利益：节省开支或债务的解除。

Principles of Valuation 估价原则

Basic Principle: Objective Market Value: The starting point for valuation is the price of the benefit (especially for services) on the open market (Benedetti v Sawiris). (例句)
基本原则：客观市场价值：估价的起点是利益（尤其是服务）在公开市场上的价格（Benedetti 诉 Sawiris 案）。(例句)

例句: The starting point for valuing the service is its objective market value – what a reasonable person would pay for one week of car cleaning in Hung Hom.
例句：估价服务的起点是其客观市场价值——一个理性人在红磡为一周的汽车清洁服务愿意支付的价格。

Subjective Revaluation: This is not accepted by the court. A plaintiff cannot demand a restitutionary award exceeding the market value just because the defendant subjectively valued the benefit more highly (Benedetti v Sawiris). (例)
主观重新估价：法院不予接受。原告不能仅因被告主观上对利益估价更高，就要求超过市场价值的返还赔偿（Benedetti 诉 Sawiris 案）。(例)
Subjective Devaluation: In principle, this is allowed to protect the defendant's autonomy. A defendant can argue that a benefit has a lower value (or even zero value) to them personally because they did not want it or it was of no use to them. If the defendant can prove that an unsolicited benefit was of little value to them personally, their restitutionary liability may be reduced. However, this right is barred if the benefit was "requested" or "freely accepted" (Benedetti v Sawiris). (例句)
主观贬值：原则上，为了保护被告的自主权，被告可以主张某项利益对其个人价值较低（甚至为零），因为他们不想要该利益或该利益对他们无用。如果被告能够证明未经请求的利益对其个人价值很低，其返还责任可能会减少。然而，如果该利益是“请求”或“自由接受”的，则该权利被排除（Benedetti 诉 Sawiris 案）。（例句）

例句: For the first week, B has a very strong argument that he should not be liable for the value of the service based on the principle of subjective devaluation, as established in Benedetti v Sawiris.
例句：在第一周，B 基于 Benedetti 诉 Sawiris 案确立的主观贬值原则，有充分理由主张他不应对该服务的价值承担责任。
However, B can argue that this benefit was imposed on him without his knowledge or consent, and he had no opportunity to reject it . To protect his personal autonomy, the law allows him to subjectively devalue the service, potentially to zero, because he did not request it. This aligns with the principle against assisting "officious intermeddler" as seen in Falcke v Scottish Imperial Insurance.
然而，B 可以辩称该利益是在他不知情或未同意的情况下强加给他的，他没有机会拒绝。为了保护其个人自主权，法律允许他对该服务进行主观贬值，甚至可能贬值为零，因为他未曾请求该服务。这与 Falcke 诉 Scottish Imperial Insurance 案中反对“多管闲事者”原则相符。
Counter-argument: Incontrovertible benefit
反驳意见：不可争辩的利益

如果被告获得了无可争议的利益，他就不能再主张主观贬值
例句: A's strongest counter-argument is that B received an incontrovertible benefit. The facts state that B's boss, C, was so impressed by the clean car that he gave B a pay rise. This pay rise is a realised financial gain that is a direct consequence of A's service. Following the logic in cases like Greenwood v Bennett , where a non-money benefit is converted into money, a court could find that B was unequivocally enriched. This incontrovertible benefit would likely defeat B's attempt at subjective devaluation. Therefore, A has a strong, albeit not certain, claim for the market value of one week's service.
例句：A 最有力的反驳是 B 获得了无可争辩的利益。事实陈述中，B 的老板 C 对干净的车印象深刻，因此给了 B 加薪。这次加薪是 A 提供服务的直接结果，是实现的经济利益。根据 Greenwood 诉 Bennett 等案件中的逻辑，非货币利益转化为货币利益，法院可能认定 B 确实获得了明确的利益。这种无可争辩的利益很可能会驳回 B 主观贬值的尝试。因此，A 对一周服务的市场价值有强有力但非绝对的索赔权。

Free Acceptance: D的沉默是否构成“自由接受”?

分析应围绕以下几点展开：

B是否有机会拒绝？(有，他看见了)
B是否知道A期望获得报酬？(A是以此为生的，这一点很可能成立)
B的沉默是否构成“选择接受”？

如果构成自由接受，那么根据 Benedetti 案，B将丧失主张“主观贬值”的权利，必须按市场价支付第二周的服务费
例句: The applicable legal principle here is Free Acceptance. A's claim would be that B, having had the opportunity to reject the benefit, freely accepted it knowing or believing that A expected payment for it.
例句：此处适用的法律原则是自由接受。A 的主张是，B 在有机会拒绝该利益的情况下，自由接受了该利益，且知道或相信 A 期望对此获得报酬。

According to the principles discussed in Benedetti v Sawiris, a defendant who freely accepts a service is barred from later arguing for subjective devaluation. By remaining silent and allowing A to continue, B implicitly accepted the service on the basis of its objective market value. His excuse of being "late for work" is unlikely to be sufficient to negate this acceptance.
根据 Benedetti 诉 Sawiris 案中讨论的原则，被告自由接受服务后，不能再主张主观贬值。B 保持沉默并允许 A 继续提供服务，隐含地接受了该服务的客观市场价值。他以“上班迟到”为由的辩解不太可能足以否定这种接受。

Valuation of Services: The key is to distinguish between the "value of the service itself" and the "value of the end product". The law generally only orders restitution for the former (Cobbe v Yeoman's Row). (例句)
服务的估价：关键在于区分“服务本身的价值”与“最终产品的价值”。法律通常仅要求对前者进行返还（Cobbe 诉 Yeoman's Row 案）。（例句）
Use Value of Money: The Sempra Metals case had allowed for the recovery of the time value of money (compound interest), but this was later overruled by the Prudential case based on a stricter "at the expense of" principle. After Prudential, claims in unjust enrichment at common law do not allow for the recovery of compound interest for the use value of money. (例句)
货币使用价值：《Sempra Metals》案允许追回货币的时间价值（复利），但随后在《Prudential》案中基于更严格的“由……承担费用”原则被推翻。Prudential 案之后，普通法下的不当得利请求不允许因货币使用价值而追回复利。（例句）
Conclusion & Advice (例句) 结论与建议（例句）

In summary, AG has a very strong claim to recover HK$50,000 for the second week based on free acceptance. Its claim for the first week is also strong, as the subsequent financial gain LSA received by securing a higher rent constitutes a powerful incontrovertible benefit that negates LSA's defence of subjective devaluation.
综上所述，AG 基于自由接受原则对第二周追回 50,000 港元的请求非常有力。其对第一周的请求也很强，因为 LSA 通过确保更高租金所获得的后续经济利益构成了强有力且无可辩驳的利益，否定了 LSA 关于主观贬值的抗辩。
Therefore, AG should be advised that it has a high prospect of recovering the full HK$100,000. LSA should be advised that its defences are unlikely to succeed and it faces a high probability of being found liable for the entire sum.
因此，应建议 AG 其有很大可能性收回全部 10 万港元。应告知 LSA 其抗辩不太可能成功，且极有可能被判承担全部款项的责任。

Step 2: Was the Enrichment at the Plaintiff's Expense? (C3)
第二步：该利益是否由原告承担？（C3）

Core Principle: The modern law requires a direct transfer of value from the plaintiff to the defendant. The facts state that P paid the money to D. This was a direct payment from P to D, satisfying the test laid out in ITC v HMRC. (例句)
核心原则：现代法律要求原告向被告直接转移价值。事实陈述中，P 向 D 支付了款项。这是 P 向 D 的直接支付，符合 ITC 诉 HMRC 案中确立的标准。（例句）

A simple "but-for" causation is insufficient and was rejected in ITC v HMRC.
简单的“如果不是因为”因果关系是不足够的，且在 ITC 诉 HMRC 案中被否定。

The General Rule (ITC v HMRC) It generally requires that the benefit was intended by the plaintiff to be provided to the defendant and was transferred directly to the defendant. (例句)
一般规则（ITC 诉 HMRC 案）通常要求该利益是原告意图提供给被告的，并且该利益是直接转移给被告的。（例句）

This excludes "incidental benefits".
这排除了“附带利益”。

Exceptions 例外情况

Agency & Sham: The law will see through the facade and treat these as direct transfers.
代理与虚假行为：法律将识破表象，将其视为直接转移。

这个原则是双向的：

原告的代理人付款：当原告 P 通过其代理人 A 向被告 D 付款时，法律视同 P 直接向 D 付款。
被告的代理人收款：当原告 P 向被告 D 的代理人 A 付款时，法律视同 D 本人直接收到了这笔款项。

The sham will be treated as a direct transfer (Relfo v Varsani)
虚假行为将被视为直接转让（Relfo 诉 Varsani）

例子：洗钱网络。表面上看，D是从一个不相关的第三方收款，与P没有直接关系。但法院会认定，这一系列复杂的中间交易是虚假的 (sham)，其唯一目的就是为了掩盖从P到D的直接支付这一事实。法院会忽略这些中间环节，将该获益直接认定为“以P为代价”。

Discharge of D's Obligation: If P pays X to discharge a debt D owed to X, then D is directly enriched by the discharge of the debt (Banque Financière, Bank of Cyprus v Menelaou). (例句)
债务人义务的解除：如果原告向 X 支付款项以解除债务人对 X 的债务，则债务人因债务的解除而直接获得利益（Banque Financière, Bank of Cyprus 诉 Menelaou）。（例句）

价值转移的路径是 P → X → D，但这是法律承认的一个例外情况

Co-ordinated Transactions: The co-ordinated transactions will be regarded as P’s discharge of D’s obligation (Banque Financière, Bank of Cyprus v Menelaou). (例句)
协调交易：协调交易将被视为原告对债务人义务的解除（Banque Financière, Bank of Cyprus 诉 Menelaou）。（例句）

例子：一位母亲想帮助她的儿子David (D) 买一套价值500万港元的公寓。她自己有另一套价值800万港元的房产，但这套房产抵押给了银行 (P)，尚有400万港元贷款未还

各方达成一个一揽子计划：(1) 银行 (P) 同意解除对其母亲房产的抵押；(2) 母亲立即出售其房产，获得800万港元；(3) 母亲用这笔钱中的400万还清对银行(P)的贷款，再用剩余的钱为儿子David (D) 支付购买新公寓的费用
在这里，没有任何一笔钱是从银行(P)直接付给David(D)的。但是，银行(P)的行为——解除对其母亲房产的抵押——是整个计划能够启动的第一推动力。

法院将这一系列相互关联、相互依存的步骤视为一个不可分割的“协同交易”或“单一计划” (single scheme) ，并认定D的获益实质上是“以P为代价”的，因为如果孤立地看待每一个步骤将是“不切实际的” (unrealistic)

Step 3: Was the Enrichment Unjust? (Unjust Factors): P must establish a legally recognized unjust factor. The applicable factor here is (X). (例)
第三步：该利益是否不当？（不当因素）：原告必须确立法律认可的不当因素。此处适用的因素是（X）。（例）

Vitiated Consent: 无效同意：

Mistake (C4) 错误（C4）

Core: Mistake is an unjust factor which is the false belief or assumption (Pitt v Holt), a misprediction of future is not a mistake (Dextra Bank v Bank of Jamaica).
核心：错误是一种不公正因素，指错误的信念或假设（Pitt 诉 Holt 案），对未来的错误预测不构成错误（Dextra Bank 诉牙买加银行案）。

例句: P paid the money under the mistaken belief that the Statue legally required it to do so. This belief was based on legal advice and prevailing industry practice. The subsequent court judgment confirmed this belief was erroneous.
例句：P 基于错误的信念支付了款项，认为该法规要求其这样做。该信念基于法律意见和当时的行业惯例。随后法院判决确认该信念是错误的。

Mistaken Payments: Based on a mistake about an obligation to pay.
错误支付：基于对支付义务的错误认识。

Test: The mistake was causative; but for its mistaken belief about its legal obligation, P would not have paid the HKD. (Kelly v Solari)
测试：该错误具有因果关系；如果不是因为其对法律义务的错误认知，原告不会支付该港币。（Kelly 诉 Solari 案）

例句: The legal test is a simple causative mistake. P only needs to show that 'but for' his mistake about the mistake fact, he would not have paid the money. This test is clearly satisfied.
例句：法律测试是一个简单的因果错误。原告只需证明“如果不是”他对错误事实的错误认识，他就不会支付这笔钱。该测试显然已满足。
P's potential "negligence" in not challenging the law sooner is irrelevant to establishing the cause of action (Kelly v Solari).
原告未能更早质疑法律的潜在“疏忽”与确立诉因无关（Kelly 诉 Solari 案）。

Bar: P can recover money paid under a mistake of fact, though P had the means of knowledge of the fact; but can’t claim if P deliberately chose not to investigate the facts (Kelly v Solari).
阻止事由：原告因事实错误支付的款项可以追回，尽管原告有能力了解该事实；但如果原告故意选择不调查事实，则不能主张追回（Kelly 诉 Solari 案）。
Miska of Fact v. Mistake of Law
事实错误与法律错误之区别

简单来说，这两种错误的主要区别在于历史。过去，只有事实错误才能让你拿回钱，法律错误则不能。但现在，法律已经进步了，在 Kleinwort Benson 案之后，这个区别在不当得利法中基本已经不存在了。如今的重点不再是区分错误的类型，而是判断是否存在一个导致了支付行为的、根本性的错误
P can recover money paid under a mistake of law (or a mistake of fact), it is not barred by the fact that the money remained to be paid (Kleinwort Benson v Lincoln CC)
原告因法律错误（或事实错误）支付的款项可以追回，且不因款项尚未支付而被阻止（Kleinwort Benson 诉 Lincoln 市议会案）。
A payment made under a mistake of law is a valid ground for restitution. (Kleinwort Benson v Lincoln CC)
因法律错误支付的款项是有效的返还理由。（Kleinwort Benson 诉 Lincoln 市议会案）

Mistaken Gifts: Based on a mistake about the motive for the gift.
错误赠与：基于对赠与动机的错误认识。

There needs to be two stages which are the rescission of the gift and the restitution of the gift.
需要两个阶段，即撤销赠与和返还赠与。

Stage 1: Rescission of the Gift
阶段一：撤销赠与

这是什么？这是在法律上使赠与行为本身失效的关键第一步。原告 (P) 并不是简单地要求被告 (D) 还钱，而是请求法院宣告，那个将财产所有权从P转移到D的法律行为（即“赠与”）存在根本性瑕疵，应当被撤销或搁置 (set aside)
为何必须有这一步？

在一个典型的错误付款案例中，付款人错误地以为自己有义务付款。由于义务从未存在，所以被告的收款从一开始就缺乏合法的依据 (legal basis)。
但在错误赠与中，情况不同。赠与人 (donor) 确实有真实的意图 (real intention) 要无偿地将财产转移给受赠人 (donee)。这个意图，即使是基于错误的动机形成的，也已经创造了一个表面上有效的法律依据，使得所有权得以转移。
因此，在可以要求返还财产之前，必须首先攻击并摧毁这个转移财产的法律依据。撤销 (Rescission) 就是这个攻击和摧毁的过程。它旨在“解除”这个有瑕疵的赠与行为

Test: sufficient gravity 标准：足够严重

Stage 2: Restitution of the Gift
阶段二：礼物的返还

这是在第一阶段成功后自然产生的法律后果
如何运作？一旦法院通过“撤销”(rescission) 使赠与行为失效，被告继续占有该财产的合法依据就不复存在了。他的获益（enrichment）现在变得“不当”(unjust)。此时，不当得利法就会介入，施加一项义务，要求被告向原告作出返还 (make restitution)。
返还的形式可以是：

人身救济 (Personal Remedy): 法院命令被告支付等同于赠与物价值的金钱。
物权救济 (Proprietary Remedy): 法院宣告被告是以推定信托 (constructive trust) 的方式为原告持有该赠与物，原告可以主张对该特定财产的权利

Test: A stricter standard is applied, requiring the mistake to be of "sufficient gravity" (Pitt v Holt).
测试：适用更严格的标准，要求错误具有“足够严重性”（Pitt v Holt）。

定义: 指赠与人清楚地知道自己在做什么（例如，他知道自己正在赠与100万给某人），但他对这个行为将带来的附带影响或结果产生了错误的认识
典型例子:

税务影响 (Tax implications): 这是最经典的例子。一个人赠与财产，却错误地以为该赠与没有税务负担，但实际上触发了巨额的税款。法院通常认为，这只是对交易后果的错误，不足以撤销赠与。
对自身财富的影响: 一个人赠与了一大笔钱，错误地以为自己剩下的钱还足够养老，但后来发现不够了。
对社会福利资格的影响: 一个人赠与财产，错误地以为这不会影响自己领取政府福利的资格

通常“能”构成足够严重性的错误：法院在 Pitt v Holt 案中指出，这个标准通常只在以下两种情况下才能满足：

(a) 对交易法律性质或效果的错误 (Mistake as to the legal character or nature of a transaction):
(a) 关于交易法律性质或效果的错误（Mistake as to the legal character or nature of a transaction）：

定义: 赠与人以为自己在进行一种法律行为，但实际上他所做的法律行为是另一种性质完全不同的东西。他的意图与法律文书的实际效果之间存在根本性的断裂
例子: 一个人以为自己只是在签署一份授权书，允许他人代为管理财产，但实际上他签署的是一份不可撤销的信托契据，将财产的实益所有权永久性地转移了出去

(b) 对交易基础性事实或法律的错误 (Mistake as to some matter of fact or law which is basic to the transaction):
(b) 关于交易基础性事实或法律的错误（Mistake as to some matter of fact or law which is basic to the transaction）：

定义: 错误触及了整个赠与行为的根基，如果这个根基是错误的，整个交易就失去了意义
对受赠人身份的错误 (Mistake as to the identity of the recipient): 正如我们之前练习题中的Wong先生一样，他以为自己是在给孙女Grace赠与，但实际上是给了邻居的女儿Chloe。受赠人的身份对于一个赠与行为来说，是绝对基础性的。
对赠与物性质的错误 (Mistake as to the nature of the subject matter): 一个人将一幅画赠与给博物馆，因为他相信这是伦勃朗的真迹。但后来发现这只是一幅没有价值的赝品。这幅画是“真迹”这一事实，是整个赠与行为的基础。

“足够严重性”并非一个可以机械套用的公式。Pitt v Holt 案最终将决定权交给了法院，要求法院进行一种全面的、评估性的判断 (evaluative judgment)。法院会综合考虑所有因素——包括错误的性质、错误的严重性、错误对赠与人造成的后果的严重性——来最终判断，如果让这个错误的赠与继续有效，是否会达到**“不合情理” (unconscionable)** 的程度
例句: The test is stricter. According to Pitt v Holt, the mistake must be of "sufficient gravity". This usually requires a mistake as to the legal character of the transaction or a matter basic to it. A mistake as to the very identity of the recipient is arguably a mistake that is fundamental and basic to a gift, not merely a mistake as to its consequences. Therefore, it is highly likely that this mistake would be considered sufficiently grave to allow restitution.
例句：该测试更为严格。根据 Pitt 诉 Holt 案，错误必须具有“足够的严重性”。这通常要求错误涉及交易的法律性质或其基本事项。关于受赠人身份的错误可以说是对赠与的根本性和基本性的错误，而不仅仅是对其后果的错误。因此，该错误极有可能被视为足够严重，从而允许返还。

Duress (C5) 胁迫（C5）

Core: Duress is an unjust factor which is the illegitimate threat or pressure over the P which had a causal effect on P’s decision to transfer the benefit (Barton v Armstrong).
核心：胁迫是不正当因素，指对原告施加的非法威胁或压力，该压力对原告决定转移利益具有因果影响（Barton 诉 Armstrong 案）。

The threats can be both explicit and implicit (The Alev).
威胁可以是明确的也可以是隐含的（The Alev 案）。

Types: 类型：

Duress to the Person & Goods
对人身及货物的胁迫

If D’s threats were one reason for P’s conduct is sufficient to establish the causative link (Barton v Armstrong)
如果 D 的威胁是 P 行为的一个原因，即足以确立因果关系（Barton 诉 Armstrong 案）
Generally, the duress can only be established when the threat is unlawful but in exceptional circumstances, it can be lawful but unreasonable (R v Attorney General for England and Wales).
通常，胁迫只有在威胁为非法时才能成立，但在特殊情况下，威胁可以是合法但不合理的（R 诉英格兰及威尔士总检察长案）。
There must be no reasonable alternatives which involve seeking legal redress (Hennessy v Craigmyle and Co).
必须不存在涉及寻求法律救济的合理替代方案（Hennessy 诉 Craigmyle and Co 案）。

Economic Duress: 它指的是威胁损害的是原告的经济利益（例如，商业合同、利润、生意机会），以区别于威胁损害人身或具体财物的胁迫。The core task is to distinguish "normal commercial pressure" from "illegitimate pressure". The court will consider factors such as threats of breach of contract, good/bad faith, and the absence of a realistic alternative (DSND Subsea).
经济胁迫：指威胁损害原告的经济利益（例如商业合同、利润、生意机会），以区别于威胁损害人身或具体财物的胁迫。核心任务是区分“正常商业压力”与“非法压力”。法院将考虑诸如违约威胁、善意/恶意以及缺乏现实替代方案等因素（DSND Subsea 案）。

Threats of breach of contract
违约威胁

例句：D的威胁是进行一项非法行为 (unlawful act)，即违约。这本身就构成了推定上的不法压力 (prima facie illegitimate pressure)

Good/bad faith 善意/恶意

善意 (Good Faith): 指施压方真诚地相信 (genuinely believed) 自己在法律上或商业上有权提出该要求。他并非在进行敲诈勒索，而是在一个真实的商业纠纷中，用合法的商业手段来维护自己认为的正当权益
恶意 (Bad Faith): 定义: 指施压方明知自己无权提出该要求，或者其行为是机会主义的 (opportunistic)，旨在利用对方的困境来获取不正当的利益

The absence of a realistic alternative
缺乏现实可行的替代方案

例句：可以补充一点：诉诸法律（如申请禁制令）在当时的情况下并不是一个现实可行 (practical) 的替代方案，因为它无法解决PCL迫在眉睫的商业需求（即按时拿到钢材以避免巨额罚款）

Lawful Act Duress: An important developing area that requires the conduct to be "reprehensible or unconscionable" (Times Travel).
合法行为胁迫：一个重要的发展领域，要求行为“应受谴责或不合理”（Times Travel）。

The lawful act economic duress includes 1) exploitation of knowledge of criminal activity and 2) maneuvering P to waive his claim (Borelli v Ting).
合法行为中的经济胁迫包括 1）利用对刑事活动的了解，2）操纵原告放弃其权利主张（Borelli 诉 Ting 案）。

Undue Influence (C5) 不当影响（C5）

Core: The abuse of a relationship of trust and confidence.
核心：滥用信任和信心关系。
Methods of Proof: 证明方法：

Actual UI: Proving improper pressure was directly exerted; no need to prove "manifest disadvantage (Aboody)" (CIBC Mortgages v Pitt).
实际不当影响：证明直接施加了不当压力；无需证明“明显不利（Aboody）”（CIBC Mortgages 诉 Pitt 案）。

证据内容: 证据通常指向某个具体的不当行为，例如：

公然的压力或胁迫 (coercion or pressure)。
故意隐瞒关键信息 (deliberate concealment)。
利用情感依赖进行威胁（例如，Aboody案中丈夫的情绪爆发）

核心: 原告需要向法官重现一个“故事”，证明“D确实对我做了不该做的事，导致我签了字”。

Presumed UI: 例句：Alternatively, a claim can be established based on Presumed Undue Influence. This requires proving two elements (Royal Bank of Scotland plc v Etridge (No 2)):
推定不当影响：例句：或者，可以基于推定不当影响提出主张。这需要证明两个要素（Royal Bank of Scotland plc 诉 Etridge（No 2）案）：

1) A relationship of trust and confidence
1）信任与信赖关系

Class 2A: 法律上自动认定的关系 (Recognized relationships of influence)：对于某些特定的关系，由于其内在的信任和影响力属性，法律自动地、不可反驳地推定 (irrebuttable presumption) 其中存在影响关系。原告无需提供任何证据来证明

父母对未成年子女 (Parent over minor child)
监护人对被监护人 (Guardian over ward)
医生对病人 (Doctor over patient)
医生凌驾于病人之上
律师对客户 (Solicitor over client)
受托人对受益人 (Trustee over beneficiary)
受托人对受益人

Class 2B: 事实上存在的关系 (Factual relationship of influence)：对于所有其他不属于Class 2A的关系（包括夫妻、同居伴侣、年迈父母与成年子女等），不存在自动推定
This is clearly established on the facts. D was P's financial advisor for over 20 years, and P "trusts D completely with all her affairs." This constitutes a Class 2B relationship of influence proven on the facts. (例句)
这一点在事实中已明确确立。D 是 P 的财务顾问超过 20 年，P“完全信任 D 处理她的所有事务。”这构成了事实证明的 2B 类影响关系。（例句）

2) A transaction that "calls for explanation"
2) 需要解释的交易

交易本身必须足够可疑，以至于不能用双方关系中的正常动机（如爱、友谊或普通的商业往来）来合理解释。正如 Turkey v Awadh [2005] 案所述，法官会问：一个普通人会做这样的事吗，除非他的意志受到了别人的不当影响？
判断标准和考量因素:

交易的性质: 纯粹的赠与 (Gifts) 比有对价的合同 (contracts) 更容易引起怀疑。
交易的规模: 交易的价值相对于原告的总资产有多大？（例如，Crédit Lyonnais Bank v Burch [1997] 案中，一个普通雇员为老板的公司提供了无限担保，这显然需要解释）。
对原告的不利程度: 交易是否对原告明显不利？虽然在Actual UI中无需证明“明显不利”，但在Presumed UI中，交易的不利性是判断其是否“需要解释”的核心证据。
夫妻担保的特殊性 (Etridge Nuance): 妻子为丈夫的生意（或反之）提供担保，其本身并不自动构成“需要解释的交易”。因为法律承认他们的经济利益通常是共同的。
妻子必须能指出一些“额外的东西” (something additional) 来证明这笔交易是不寻常的。例如：丈夫的公司已经濒临破产，担保行为毫无商业上的合理性。或者妻子被要求承担的风险（如无限担保）与她可能获得的任何间接利益完全不成比例。

This element is also clearly satisfied. A gift of HK$2,000,000, which represents over 80% of P's life savings, made to her financial advisor is not a normal transaction. It is so large and improvident that it "calls for an explanation" and cannot be accounted for by ordinary motives of friendship or charity. (例句)
该要素也显然已满足。向其财务顾问赠送 200 万港元的礼物，占 P 终生积蓄的 80%以上，这并非正常交易。金额如此巨大且不明智，“需要解释”，不能用普通的友谊或慈善动机来说明。（例句）

Since both elements are met, a presumption of undue influence arises. The burden of proof would then shift to D to rebut it, for example by proving P received independent legal advice. On these facts, D cannot do so. Therefore, the claim would also succeed on the basis of presumed undue influence. (例句)
既然两个要素均已满足，则产生不当影响的推定。举证责任随后转移至被告，以反驳该推定，例如证明原告已获得独立法律咨询。根据这些事实，被告无法做到。因此，该诉求也可基于推定的不当影响而成立。（例句）
银行是否对这种情况被置于查询之上 (put on inquiry)

根据权威案例 Royal Bank of Scotland plc v Etridge (No 2)，当一个妻子（或处于类似情感依赖关系中的人）为其丈夫（或有影响力的一方）的债务提供担保，且该交易对她没有直接商业利益时，银行就自动地被置于查询之上。在本案中，父亲为儿子的公司作保是典型情况。
一旦银行被置于查询之上，它必须采取合理的步骤 (reasonable steps) 来确保担保人是在没有受不当影响的情况下自愿签字的，最核心的步骤就是坚持要求担保人（Mr. Au）获得独立的法律意见。

"No Consent" Factors: “无同意”因素：

Ignorance (C8): Occurs when property is transferred entirely without the plaintiff's consent (e.g., theft) (Lipkin Gorman v Karpnale Ltd).
无知（C8）：指财产完全在原告不知情且无同意的情况下被转移（例如盗窃）（Lipkin Gorman 诉 Karpnale Ltd 案）。

明确三方关系: 你可以更明确地指出，这是一个经典的三方关系 (P → X → D) 案例，即P的财产通过中间人X（小偷）转移给了最终的收款人D。并说明，即使转移不是直接的，不当得利之诉仍然可以成立。因为不当得利之诉通常是严格责任 (strict liability)
提及并行索赔: 在这种情况下存在并行责任 (concurrent liability)。一个更完整的答案会提及，除了不当得利之诉，P同样可以对D提起侵权法下的侵占之诉 (tort of conversion) 或物权主张 (proprietary claim) 来要求返还手表本身

例句: In addition to the claim in unjust enrichment based on the unjust factor of Ignorance, it is important to note that a concurrent liability arises on these facts. The defendant's act of taking possession of the watch and refusing to return it also constitutes the tort of conversion. Therefore, the plaintiff is not confined to a single cause of action and may choose to pursue the claim that is most advantageous to them, whether in unjust enrichment or in tort. This choice may be influenced by factors such as the different requirements for proof, the available remedies, or the applicable limitation periods for each claim.
例句：除了基于无知这一不当因素提出的不当得利请求外，还应注意，在这些事实基础上会产生并存的责任。被告占有手表并拒绝归还的行为也构成侵权行为中的非法占有。因此，原告并不限于单一的诉因，可以选择对其最有利的诉讼途径，无论是不当得利还是侵权。此选择可能受不同的举证要求、可用的救济措施或各诉讼请求适用的时效期间等因素影响。

Want of Authority (C8): Occurs when an agent acts beyond their authority (Lipkin Gorman).
无权代理（C8）：指代理人超越其权限的行为（Lipkin Gorman 案）。

注意：不当得利之诉是向获益方（通常是第三方）提起的
P 当然可以另外向转移方提起诉讼，但那将是基于违反信义义务 (breach of fiduciary duty) 的索赔，而不是基于UE的返还之诉
例句: Therefore, as D was unjustly enriched at P's expense due to X's want of authority, P can bring a claim in unjust enrichment against D to recover the benefit.
例句：因此，由于 X 的无权代理导致 D 在 P 的费用下不当得利，P 可以针对 D 提起不当得利诉讼以追回该利益。

Policy-Motivated Factors:
政策驱动因素：

Total Failure of Consideration (C6, C7)
对价完全失败（C6，C7）

例句: P has a strong claim in unjust enrichment against D for the restitution of the benefit. The applicable unjust factor is Total Failure of Consideration (TFC).
例句：P 对 D 提出不当得利返还利益的主张具有很强的依据。适用的不当因素是对价完全失败（TFC）。
Core Concept: The "basis" or "purpose" of a payment has failed. The "consideration" here means actual performance, not the contractual promise (Fibrosa).
核心概念：付款的“基础”或“目的”已失败。此处的“对价”指实际履行，而非合同承诺（Fibrosa 案）。

The consideration for P‘s payment was the promised action by D. Following D's anticipatory repudiatory breach and P's acceptance of that breach, the contract was terminated. As D will now provide zero action, the basis upon which the payment was made has entirely failed. This constitutes a total failure, giving rise to a prima facie right to restitution (Fibrosa).
P 付款的对价是 D 承诺的行为。因 D 的预期违约及 P 对该违约的接受，合同被终止。由于 D 将不再提供任何行为，付款的基础已完全失败。这构成对价的完全失败，产生了返还的初步权利（Fibrosa 案）。
Old Law: Chandler v Webster
旧法：Chandler 诉 Webster 案

Requirement of "Total" Failure: The traditional rule requires the failure to be total. However, courts may get around this strict requirement to achieve fairness by defining a benefit as
“完全”失败的要求：传统规则要求失败必须是完全的。然而，法院可能通过将利益定义为

"Incidental Benefit" (Rowland v Divall)
“附带利益”（Rowland 诉 Divall 案）

核心规则: 当原告 (P) 事实上从被告 (D) 那里获得了一些好处时，如果法院认定这个好处只是附属于 (incidental to) 合同的核心或根本目的 (core or essential purpose)，而非核心目的本身，那么这个好处的存在并不会阻止法院认定发生了“对价的完全落空”

如何运作: 法院会首先通过解释合同，来定义双方交易的核心对价是什么。然后，它会审视原告获得的好处。如果这个好处并非那个被定义为“核心”的东西，它就会被法律“无视”，从而使得对价的失败被视为“完全的”
权威案例是 Rowland v Divall [1923]。在该案中，法院认定买方付款的核心对价是为了获得汽车的合法所有权，而对汽车本身的物理使用，只是拥有所有权后自然产生的一个“附带利益”

例句: D's primary defence is that the failure of consideration was not total, because it had performed part of its contractual obligation by doing something. While the traditional rule requires the failure to be "total," this argument will likely fail based on the principle established in Rowland v Divall.
例句：被告的主要抗辩是对价失败并非完全失败，因为其已通过履行部分合同义务而完成了一些工作。尽管传统规则要求失败必须是“完全的”，但根据 Rowland 诉 Divall 案确立的原则，该抗辩很可能会失败。

The rule in Rowland v Divall allows a court to find a total failure of consideration even if the plaintiff has received some factual benefit, provided that benefit is merely incidental to the core purpose of the contract.
Rowland 诉 Divall 案中的规则允许法院即使原告获得了一些事实上的利益，也可以认定对价完全失败，前提是该利益仅是合同核心目的的附带结果。
The court must first construe the contract to determine what the essential bargain was. Here, P paid HK$80,000 for a specific property. The core consideration was the acquisition of good legal title to this specific and valuable piece of property.
法院必须首先解释合同，以确定基本交易内容。在本案中，P 支付了 80,000 港元购买一处特定物业。核心对价是获得该特定且有价值物业的合法所有权。
The extra service, while having a market value, was entirely ancillary and subordinate to the core purpose of owning the poster. The value of this extra service is predicated on the property. Only the extra service is of no value to P.
额外服务虽具有市场价值，但完全是附属且从属于拥有该海报的核心目的。该额外服务的价值依赖于该物业。仅有额外服务对 P 没有价值。
Since the core consideration has completely failed, the extra service is properly classified as an incidental benefit. The existence of this incidental benefit does not prevent a finding of a total failure of consideration.
由于核心对价已完全失败，额外服务应被正确归类为附带利益。该附带利益的存在不妨碍认定对价完全失败。

Treating obligations as "severable" (Roxborough)
将义务视为“可分割的”（Roxborough）

规则定义: 该规则适用于一个总的合同价款，可以被清晰地分解和归属 (apportioned) 到合同中几个不同的、独立的部分。当这种情况发生时，每一部分都被视为一个小型的、独立的交易
如何判断: 法院会审视合同的条款和双方的意图，判断总价款究竟是一个不可分割的“一口价”(lump sum)，还是一个由几个明确部分加总而成的总和。最明显的证据就是价格的构成方式，例如在发票或协议中明确列出“项目A：XX元，项目B：YY元”

Breach of Contract: Claim by Innocent Party (Escape a "bad bargain")
违约：无过错方的索赔（逃避“糟糕交易”）

"Bad/Losing bargain": Had the contract been performed, P stood to make a significant financial loss (例句)
“糟糕/亏损交易”：若合同履行，原告将遭受重大经济损失（例句）
Whether P’srestitutionary claim for the payment is limited or "capped" by the contractual price, preventing P from using the law of unjust enrichment to escape a bad bargain? (Mann v Paterson) (例句)
原告的返还请求是否受合同价格限制或“上限”，从而阻止原告利用不当得利法逃避糟糕交易？（Mann 诉 Paterson）（例句）

“合同上限”原则的目的是为了尊重双方在合同中对风险的原始分配，防止无过错方利用对方的违约行为，来获得比他履行合同本应得到的还要多的利益。
因此，这个“上限”不是简单地直接套用合同的总价，而是要看：如果合同没有被终止，VM在完成了那部分工作后，根据合同他本应得到多少钱？“合同上限”原则的目的是为了尊重双方在合同中对风险的原始分配，防止无过错方利用对方的违约行为，来获得比他履行合同本应得到的还要多的利益。
因此，这个“上限”不是简单地直接套用合同的总价，而是要看：如果合同没有被终止，VM在完成了那部分工作后，根据合同他本应得到多少钱？比如完成了一半的工作就终止了，那就应该对应合同中总工钱的一半

D would strongly argue that the contract price must act as a cap on any restitutionary award. (例句)
D 将强烈主张合同价格必须作为任何返还性赔偿的上限。 (例句)

The law of unjust enrichment should not be used to subvert the allocation of risk freely agreed to by the parties in their contract. The contract price reflected the commercial risk P was willing to assume. To allow P to recover her full pre-payment would put her in a better position than if the contract had been performed, thereby giving her a windfall at the expense of D.
不当得利法不应被用来颠覆双方在合同中自由约定的风险分配。合同价格反映了原告愿意承担的商业风险。允许原告全额追回预付款，将使其处于比合同履行时更有利的地位，从而使其获得不当得利，损害被告利益。

In response, P has several powerful counterarguments. (例句)
作为回应，原告有几个有力的反驳理由。 (例句)

First, it was D, the party in breach, who repudiated the contract. He cannot destroy the contractual regime with his own wrongful act and then selectively seek to rely on a term from that same contract to limit his liability.
首先，违约方是被告，他单方面拒绝履行合同。被告不能通过自己的不当行为破坏合同体系，然后选择性地依赖同一合同中的条款来限制其责任。
Second, P’s claim is not in contract but in unjust enrichment, a separate cause of action. A non-contractual remedy should not be constrained by a contractual term.
其次，原告的诉求不是基于合同，而是基于不当得利，这是一个独立的诉讼理由。非合同救济不应受合同条款的限制。
Third, allowing D, the wrongdoer, to retain the money for which he has provided nothing would itself be a manifest injustice, and the law's primary concern in a TFC claim is to reverse that specific unjust enrichment.
第三，允许被告这一不法行为人保留其未提供任何对价的款项，本身就是明显的不公正，而法律在不当得利诉讼中的主要关注点是纠正该特定的不当得利。

On balance, the modern trend articulated in Mann v Paterson leans towards ensuring coherence between contract and unjust enrichment law. (例句)
综合来看，Mann 诉 Paterson 案中阐述的现代趋势倾向于确保合同法与不当得利法之间的一致性。

A court would likely find the reasoning that the contractual risk allocation should be respected to be highly persuasive.
法院很可能会认为应尊重合同风险分配的理由具有很强的说服力。
However, the "contract cap" is primarily aimed at preventing a plaintiff from claiming a quantum meruit award that is higher than the pro-rata contract price. Here, P is not seeking to profit; she is seeking the return of a specific sum for which the consideration has completely failed. The most direct and just response to a TFC is to return the money paid for the failed basis. Denying recovery of the pre-payment would unjustly enrich B, the contract-breaker.
然而，“合同上限”主要是为了防止原告请求超过按比例计算的合同价格的合理报酬。在此，P 并非寻求获利；她寻求的是返还因对价完全失败而支付的特定金额。对完全失败的对价（TFC）最直接且公正的回应是返还为失败基础支付的款项。拒绝返还预付款将不公正地使违约方 B 受益。

Therefore, it is highly likely that a court would find that P is entitled to the restitution of her full payment, notwithstanding the fact it was a losing bargain. (例句)
因此，法院极有可能认定，尽管这是一个失败的交易，P 有权获得其全额付款的返还。（例句）

Breach of Contract: Claim by Party in Breach
违约：违约方的索赔

In principle, a party in breach can also claim for failure of consideration, provided the payment was not a "non-refundable deposit," but the claim is subject to a set-off for damages caused to the other party (Dies v British International Mining).
原则上，违约方也可以因对价失败提出索赔，前提是付款不是“不可退还的定金”，但该索赔须抵销对另一方造成的损害赔偿（Dies 诉英国国际矿业案）。

部分支付/分期付款 (Part-payment / Instalment):

目的: 其唯一目的是作为总价款的预先支付。
法律后果: 如果合同最终因付款方的违约而被终止，由于他将无法获得对价（货物或服务），他原则上可以基于“对价完全落空”要求返还这笔款项

定金 (Deposit): 定金：

双重目的: 定金不仅是总价款的一部分，它还有一个更重要的功能，即作为付款方将会履行合同的担保 (guarantee or "earnest")
法律后果: 合同双方通常会（明示或默示地）约定，如果付款方违约，这笔定金将被没收 (forfeited)，作为对无过错方因合同被破坏而受损失的预先补偿。因此，一个被认定为真正的定金，通常是不可退还的 (non-refundable)。违约方不能以“对价落空”为由要求返还，因为“被没收”正是他违约所应承担的、双方已同意的合同后果

抵销 (Set-off): 抵销：

确立返还权: 法院首先认定，买方 (P) 支付的10万英镑是部分支付，而非定金。由于他最终无法获得军火，发生了对价完全落空，因此他拥有一个初步的权利 (prima facie right) 要求返还全部10万英镑
确立索赔权: 同时，卖方 (D) 作为无过错方，有权就因P违约而遭受的一切损失（如利润损失、仓储费等）提起损害赔偿之诉
进行抵销 (Set-off): 法院将这两个请求放在一起进行“结算”

如果卖方的总损失经计算为4万英镑，那么他需要向买方返还6万英镑 (£100,000 - £40,000)
如果卖方的总损失高达12万英镑，那么买方不仅一分钱也拿不回来，还需要额外再向卖方支付2万英镑的损害赔偿

FOC II (C7) FOC II（C7）

合同落空 (Frustration)

当一个有效的合同签订后，因发生非任何一方过错的、不可预见的根本性事件，导致合同无法履行或履行变得与初衷完全不同时，合同即告“落空”
普通法的问题 (The Common Law Problem):
普通法的问题：

在成文法介入前，普通法对此的处理方式非常僵硬，即“损失归于其所在” 。这意味着预付款通常无法追回（除非像Fibrosa案那样完全没收到任何东西），而已完成的部分工作也得不到报酬（如Cutter v Powell案），这极不公平。

香港的成文法解决方案：《法律修订及改革（综合）条例》(LARCO)

LARCO取代了普通法的僵硬规则，提供了一套更公平、更灵活的清算机制。在考试中，只要案情涉及合同落空，你就必须直接应用LARCO的条文

1. 处理金钱支付：s.16(2)

自动返还: 在合同落空前支付的所有款项，原则上都可以追回；而应付但未付的款项，则无须再支付。这彻底废除了普通法下“必须完全失败”才能返还的严苛要求
费用扣除 (The Proviso): 法院拥有酌情权，可以允许收款方从应返还的款项中，扣除其为履行合同而合理产生的费用

如何行使酌情权: Gamerco案是关键判例。法院会进行一个整体的公平判断，而不是简单的损失均分。法院会考虑所有情况，包括付款方自己是否也遭受了巨大损失。如果允许扣除费用会对付款方造成不公，法院可以裁定不予扣除。
上限: 扣除的费用总额不能超过已支付或应付的预付款总额

2. 处理非金钱利益（服务、工程）：s.16(3)

目的: 解决Cutter v Powell式的不公，即为提供部分履行（如建造了一半的房屋）的一方提供获得补偿的途径。
权威解释：Goff法官在BP Exploration v Hunt (No.2)案中的三步分析法是处理此类问题的金标准

第一步：识别利益 (Identification of Benefit):
第一步：识别利益（Identification of Benefit）：

Goff法官认为，法条所指的“利益”，不是服务的过程，而是服务所产生的最终产品 (end product) 。例如，不是“建造的行为”，而是“半建成的房屋”

第二步：评估利益价值 (Valuation of Benefit):

这是为了给最终的补偿金设定一个上限。
评估时点: 价值评估的时间点是合同落空的那一刻。
落空事件的影响: 必须考虑落空事件对“最终产品”价值的影响。如果落空事件（如地震）将最终产品（半建成的房屋）完全摧毁，那么其在落空时的价值就是零。这意味着风险由提供服务的一方承担。
费用扣减: 在计算上限时，还必须扣除利益接收方自己为履行合同而产生的费用 (s.16(3)(a))

第三步：评定公正款项 (Assessment of the Just Sum):

在确定了上限后，法院行使其最终的酌情权，在上限之内判给一个“公正的”数额
评估基础的转变: 在这一步，法院评估的不再是“最终产品”，而是提供方所付出的服务本身的价值 (value of the service)
合同价格上限 (Contract Cap): 这个服务价值通常会受到原合同价格的限制，以尊重双方最初的风险分配

无效合同 (Void Contracts) 无效合同（Void Contracts）

定义: 合同自始（ab initio）就不具有任何法律效力，通常因为重大错误、严重违法性或无行为能力等原因。
与不当得利的关系: 因为合同从未有效存在过，任何基于该“合同”的付款或履行的法律基础也就不存在。这构成了典型的对价完全落空。
核心原则 Guinness Mahon: 法院认为，当事人付款的基础，不仅仅是期望对方也付款，而是期望双方都处在一个有法律约束力的、可强制执行的合同关系中。当合同被宣告无效时，这个基础就完全失败了。

不存在的合同 (Non-existent Contracts)
不存在的合同（Non-existent Contracts）

典型情景: 双方处于合同前谈判阶段，一方应另一方的请求 (request)，提前开始工作，但由于关键条款缺乏确定性 (want of certainty)，双方最终未能达成一份有约束力的合同
法律基础 British Steel v Cleveland Bridge
法律依据 British Steel v Cleveland Bridge

由于没有合同，不能以违约为由索赔
救济的基础是不当得利，不当因素是对价完全落空——即提供服务所期望换取的那个“最终会成立的合同”落空了
请求权成立的关键是：(1) 工作是在对方的请求下进行的；并且 (2) 双方有共同的预期，即将会签订一份正式合同

答题框架 (Answering Framework) 当案例分析题涉及一个有缺陷的合同时，你可以遵循以下框架：

第一步：识别合同缺陷 & 法律后果

合同落空 (Frustration)

分析: 案情是否涉及一个在合同签订后发生的、非任何一方过错的、根本性的、不可预见的外部事件？（例如，标的物毁灭、政府禁令、核心目的消失）
法律后果: 合同自动终止。双方的权利清算必须适用LARCO

无效合同 (Void Contract) 无效合同

分析: 合同是否因重大错误、严重违法性、无行为能力等原因，从一开始就无效？
法律后果: 合同在法律上从未存在。任何履行的返还问题，由普通法下的不当得利管辖

不存在的合同 (Non-existent Contract)
不存在的合同

分析: 双方是否因为缺乏确定性（如价格、标的等关键条款未定）而从未达成合意？
法律后果: 双方之间没有合同关系。任何已提供服务的补偿问题，由普通法下的不当得利管辖

第二步：确立不当得利之诉

不当因素: 明确指出本案的核心不当因素是“对价完全落空”(Total Failure of Consideration)
阐述失败的基础:

对于落空合同: “基础”是合同的完全履行
对于无效合同: “基础”是存在一个有法律约束力的合同关系 (Guinness Mahon)
对于不存在的合同: “基础”是那个最终会签订的正式合同 (British Steel)

指出由于合同缺陷，这个基础已经失败，因此被告的获益是“不当的”

第三步：应用具体的返还规则

如果适用LARCO (因合同落空)

金钱支付? -> s.16(2): 原则上可全额追回，但法院有权根据Gamerco案的原则，在“公正”的前提下，允许对方扣除合理费用
非金钱利益? -> s.16(3): 严格遵循Goff法官的三步法：(1) 识别最终产品；(2) 评估其在落空时的价值（考虑落空事件的影响）；(3) 在上限内，判给一项基于服务价值的公正款项

如果适用普通法 (因合同无效或不存在)

返还金钱? -> 请求返还已支付的款项
补偿服务? -> 提出quantum meruit（按劳计酬）

评估获益: 讨论获益的客观市场价值 (Benedetti)
区分服务与成果: 明确获益是“服务本身”，而非“最终成果” (Cobbe)
预演抗辩: 分析被告是否能成功主张主观贬值
提出反驳: 分析原告是否能通过证明无可争议的利益或自由接受来推翻主.subjective devaluation的抗辩
得出最终的、合理的返还数额

Illegality (as a cause of action) (C10)
非法性（作为诉讼理由）（C10）

Protected Class: A party whom the law intends to protect (e.g., a tenant) can recover an illegal payment (Kiriri Cotton).
受保护类别：法律意图保护的一方（例如，租户）可以追回非法支付款项（Kiriri Cotton）。

“受保护阶层”原则本身已经解决了违法性的问题，它使得双方当事人不再被视为“同等有过错”(in pari delicto)。“当法院认定原告属于“受保护阶层”时，法律已经做出了一个政策上的权衡，即认为“保护弱者”的政策优先于“不帮助违法者”的政策。被告不能再反过头来以“交易违法”作为抗辩。因此，无需再进行一个关于违法性抗辩的 Patel v Mirza 分析

例句: Therefore, because P falls within the protected class that the Ordinance is designed to protect, D's defence of illegality will fail, and P can recover the excess interest paid
例句：因此，由于原告属于该条例旨在保护的受保护群体，被告以非法为由的抗辩将失败，原告可以追回多付的利息

Withdrawal: Before an illegal purpose has been substantially carried into effect, a party may withdraw and claim restitution (Tribe v Tribe).
撤回：在非法目的尚未实质性实现之前，当事人可以撤回并请求返还（Tribe 诉 Tribe 案）。

在这一原则下，只要非法的最终目的（比如是否实际欺骗到债权人）尚未被执行，当事人就可以自愿退出并要求返还财产。他退出的动机是自私还是悔悟，完全不相干 (irrelevant)

Incapacity (C10): A party's lack of capacity to contract due to legal reasons constitutes an unjust factor in itself. (Auckland Harbour Board v R)
无行为能力（C10）：当事人因法律原因缺乏订立合同的能力，本身构成不公正因素。（Auckland Harbour Board 诉 R 案）

Minority 未成年人

关于未成年人合同的规则比较复杂，主要分为三类，并且受到香港本地成文法的调节

必需品合同 (Contracts for Necessaries)
必需品合同

规则: 为了保障未成年人的基本生活，他们为购买“必需品”（如食物、住所、教育等）而签订的合同是有效的、有约束力的。这意味着商家可以向未成年人追讨必需品的合理价款
例句: Contracts for necessaries are generally binding on a minor. A "necessary" is defined as goods suitable to the minor's condition in life and their actual requirements at the time of sale
例句：为未成年人提供生活必需品的合同通常对未成年人具有约束力。“必需品”被定义为适合未成年人生活状况且符合其在销售时实际需求的物品。

可被废除的合同 (Voidable Contracts)

规则: 这类合同涉及具有长期性或持续性义务的重大交易（如租约、购买公司股份、合伙协议）。合同在签订时有效，但未成年人有权在年满18岁时或之后的合理时间内，单方面废除 (repudiate) 合同
返还限制: 根据 Steinberg v Scala (Leeds) Ltd 的原则，即使未成年人废除了合同，他们通常也不能要回已经支付的钱，除非发生了对价完全落空

不可强制执行的合同 (Unenforceable Contracts)

规则: 这是范围最广的一类，包括所有购买非必需品（如奢侈品）的合同。这类合同对未成年人完全没有约束力，除非他在成年后明确地“追认”(ratify) 该合同
例句: A high-end gaming computer used for leisure is clearly a luxury item and not a necessary. Contracts for non-necessaries are generally unenforceable against a minor.
例句：用于休闲的高端游戏电脑显然是奢侈品，而非必需品。针对非必需品的合同通常对未成年人不具强制执行力。

香港成文法规则 (Hong Kong Statutory Rule)
香港成文法规则

Age of Majority Ordinance (Cap 410): Section 4(1) of this Ordinance gives the court a discretionary power to order the minor to return any property acquired under the contract, if it is "just and equitable" to do so.
成年年龄条例（第 410 章）：本条例第 4(1)条赋予法院酌情权，若“公正合理”，可命令未成年人返还根据合同取得的任何财产。

例句: A court would likely find it "just and equitable" to order the restitution of the HK$25,000 to Leo's parents, conditional upon Leo returning the gaming computer to CyberStore.
例句：法院很可能会认为“公正合理”，命令将港币 25,000 元返还给 Leo 的父母，条件是 Leo 将游戏电脑归还给 CyberStore。

目的: 这条规定是为了防止未成年人滥用法律保护，既不付款，又保留货物，从而自己不当得利

Mental Incapacity 精神无行为能力

英国和香港的立场 (The UK / Hong Kong Position) (Imperial Loan Co v Stone)
英国和香港的立场（The UK / Hong Kong Position）（Imperial Loan Co 诉 Stone 案）

规则: 合同仅仅是可被撤销的 (voidable)，并且必须同时满足两个条件才能被撤销：

1. 该方在签约时确实因精神问题而缺乏理解能力；并且
2. 合同的另一方知道 (knew) 这一情况。

加拿大/新西兰的立场 (The Canadian / New Zealand Position)
加拿大/新西兰的立场

规则: 采取了更偏向于保护无行为能力者的方法。只要能证明签约一方在当时确实缺乏行为能力，合同就可以被撤销，无论另一方是否知情。

Company acting ultra vires
公司行为超越权限

在过去，公司的权力被严格限制在其《组织章程》规定的范围内。任何超出公司经营范围的合同都被视为“越权” (ultra vires)，因此是自始无效的 (void ab initio) (HKN Investoy v Incotrade Pvt Ltd)
为了促进商业活动的确定性和保护善意第三方，现代公司法已经极大地限缩或废除了越权规则对外部交易的效力。这意味着，现在一个与公司交易的善意第三方，通常不再需要担心该交易是否超出了公司的经营范围

醉酒 (Intoxication): 当事人醉到完全不能明白自己在做什么，并且对方知道其醉酒状态时，签订的合同是可被撤销的 (Gore v Gibson)
公司非法返还资本 (Companies unlawfully returning capital): 公司在没有足够利润的情况下向股东派发股息或非法回购股份，这是一种违反资本维持原则的无行为能力行为，公司（或其清盘人）可以向股东追回款项 (Payne / Goff & Jones)
清盘程序开始后的资产处置 (Dispositions after the commencement of winding up): 公司在清盘程序开始后对其财产的任何处置，除非得到法院许可，否则一律无效 (Rose v AIB Group (UK) Plc)
不当估值交易 (Transactions at an undervalue): 公司在破产前夕以远低于市场价的价格出售资产，该交易可被清盘人申请撤销 (Phillips v Brewin Dolphin Bell Lawrie)

Step 4: Are there any Applicable Defences? Even if the plaintiff proves the first three steps, the defendant may still raise a defence to escape or reduce liability.
第四步：是否存在任何适用的抗辩？即使原告证明了前三个步骤，被告仍可提出抗辩以逃避或减轻责任。

1. Illegality (as a defence) (C10)
1. 非法性（作为抗辩）（C10）

Old Law: The "reliance principle" (Tinsley v Milligan).
旧法：“依赖原则”（Tinsley 诉 Milligan 案）。
初步诉因例句: P has a prima facie claim for restitution based on the unjust factor of Mistake, as P’ action. The central issue is whether D can defeat this claim by raising the defence of illegality
初步诉因例句：P 基于错误这一不当得利因素对返还提出初步诉因，因 P 的行为。核心问题是 D 是否能通过提出非法性抗辩来驳回该诉求。
New Law (UK & HK): Following the Court of Appeal's decision in Monat Investment Ltd, a Hong Kong court would apply the flexible, policy-based "trio of considerations" framework established in Patel v Mirza.
新法（英国及香港）：继 Monat Investment Ltd 案上诉法院判决后，香港法院将适用 Patel 诉 Mirza 案确立的灵活、基于政策的“三重考量”框架。

(a) The Underlying Purpose of the Prohibition
（一）禁止的根本目的

例句: The prohibition transgressed is against tax evasion. The purpose of tax laws is to ensure the proper collection of public revenue and maintain the integrity of the fiscal system. Denying the claim could arguably serve as a deterrent to others considering similar schemes.
例句：所违反的禁令是针对逃税。税法的目的是确保公共收入的适当征收并维护财政体系的完整性。拒绝该请求可以说有助于威慑其他考虑类似方案的人。
例句: However, in this case, the illegal purpose was never carried into effect. No tax was actually evaded as the final payment, which was the subject of the illegal structuring, was never made. Therefore, allowing restitution to unwind the transaction would not directly undermine the purpose of the tax legislation.
例句：然而，在本案中，非法目的从未付诸实施。由于最终支付款项（即非法结构安排的标的）从未支付，实际上并未逃税。因此，允许返还以撤销交易不会直接破坏税法的目的。

(b) Other Relevant Public Policies
（二）其他相关公共政策

例句: This is where the analysis weighs heavily in P's favour. Denying her claim would conflict with at least two other important public policies:
例句：这正是分析明显有利于原告的地方。拒绝她的请求将与至少另外两项重要的公共政策相冲突：

The policy of preventing unjust enrichment: This is the very foundation of P’s claim. If the defence succeeds, the party who breached the contract would be unjustly enriched for which he provided no performance whatsoever. The law has a strong interest in reversing such a windfall.
防止不当得利的政策：这是原告主张的根本依据。如果被告的抗辩成功，违约方将因未提供任何履行而获得不当得利。法律对此类意外之财有强烈的纠正意愿。
The policy of upholding contractual remedies: D committed a repudiatory breach of contract. The law gives the innocent party the right to terminate the contract and seek appropriate remedies. To bar P’s restitutionary claim on grounds of illegality would effectively punish her (the innocent party to the breach) while rewarding the contract-breaker. This would create an incoherent outcome where the law of contract and the law of unjust enrichment are pulling in opposite directions.
维护合同救济的政策：被告实施了根本性违约。法律赋予无辜方终止合同并寻求适当救济的权利。以违法为由禁止原告的返还请求，实际上是惩罚无辜的违约方一方，同时奖励违约者。这将导致合同法与不当得利法相互矛盾的结果。
When balancing these policies, the policies of preventing a windfall to a contract-breaker and upholding an innocent party's rights appear to significantly outweigh the policy of deterring an inchoate illegal act that caused no public harm.
在权衡这些政策时，防止违约方意外获利和维护无辜方权利的政策明显优于遏制未成形且未造成公共危害的非法行为的政策。

在什么情况下，法院会觉得“让原告败诉、一分钱都拿不到”是公平合理的？

原告在寻求强制执行一份非法的协议，并从中获取利润
如果原告只是想拿回自己的本金，拒绝他通常是不相称的。
如果原告的违法行为很轻微，拒绝他通常是不相称的。

例句: Finally, the court must consider whether denying the claim would be a proportionate response to the illegality. While Elara knowingly entered into the illegal arrangement, several factors suggest denial would be disproportionate:
例句：最后，法院必须考虑拒绝该请求是否对违法行为构成相称的回应。尽管 Elara 明知故犯地参与了非法安排，但有几个因素表明拒绝请求将是不相称的：

She is not seeking to profit from the illegality: Her claim is restitutionary in nature; she is seeking to unwind the transaction and recover her own money, not to enforce the illegal scheme or claim profits from it.
她并非寻求从违法行为中获利：她的请求具有返还性质；她寻求撤销交易并收回自己的资金，而非执行非法方案或索取利润。
The illegal act was not performed: The harm was potential, not actual.
非法行为未被实施：损害是潜在的，而非实际发生的。

To allow Benny to keep the money would be a disproportionate penalty on Elara for her involvement in an unperformed illegal clause.
允许 Benny 保留这笔钱将对 Elara 因参与未实施的非法条款而施加不相称的惩罚。

The outcome would be a windfall for the wrongdoer: Denying the claim would result in a HK$1,000,000 windfall for Benny, who was not only a willing participant in the illegal clause but also the party whose own breach of contract caused the arrangement to collapse.
结果将成为不当得利：拒绝该请求将使 Benny 获得 100 万港元的意外之财，而 Benny 不仅是非法条款的自愿参与者，还是因自身违约导致该安排崩溃的一方。

Conclusion: Weighing the trio of considerations, the illegality defence is very likely to fail.
结论：权衡这三方面的考虑，违法抗辩很可能会失败。

例句: Allowing restitution would not stultify the purpose of the tax laws, is strongly supported by the competing public policies of preventing unjust enrichment and upholding contractual rights, and denying the claim would be a disproportionate outcome. Therefore, Elara should be able to overcome the illegality defence.
例句：允许返还不会阻碍税法的目的，且强烈支持防止不当得利和维护合同权利的相互竞争的公共政策，拒绝该请求将导致不成比例的结果。因此，Elara 应能克服违法抗辩。

2. Change of Position (C11)
2. 立场变更（C11）

Core Defence: The defendant, in good faith, has changed their position in reliance on the receipt of the benefit, such that it would be inequitable to require full restitution (Lipkin Gorman). (例句)
核心抗辩：被告善意地基于已收到利益而改变了其立场，以至于要求其完全返还将不公平（Lipkin Gorman）。(例句)
The D must prove (Zhang Kan):
被告必须证明（Zhang Kan）：

(1) there was a causative link between the receipt of the benefit and its change of position;
(1) 收益的获得与其立场的改变之间存在因果关系；

A "but-for" test is required
需要采用“如果不是……就不会……”的因果关系检验。
There can be independent changes of position caused by the third party rather than D. e.g. if the money is “stolen, fraudulently misappropriated, lost or destroyed”, the full restitution will be inequitable (Credit One Finance Ltd v Yeung Kwok Chi).
第三方而非被告造成的独立立场变动亦可存在。例如，如果款项被“盗窃、欺诈性挪用、丢失或毁坏”，则全额返还将不公平（Credit One Finance Ltd 诉 Yeung Kwok Chi）。

(2) position has changed and makes it inequitable for it to be required to make restitution to P.
（二）立场已发生变化，要求其向原告返还款项将不公平。

There is no Change of Position if the expenditure is not extraordinary (Scottish Equitable v Derby).
若支出并非异常，则不构成立场变动（Scottish Equitable 诉 Derby）。
The burden is on D to prove while a realistic approach is adopted (Phillip Collins v Davis).
举证责任在被告，且采取现实主义方法（Phillip Collins 诉 Davis）。

A realistic approach是指法院在审理“处境变更”抗辩时，不会对被告（收款方）施加一个不切实际的、过分严苛的举证标准。被告不需要提供每一笔花销的单据来“决定性地”或“无可辩驳地”证明其处境变更。
被告可以通过多种方式来证明，例如提供银行结单显示其总体支出水平提高、描述其生活方式的改变（例如，开始去更昂贵的餐厅、度假次数增多等），并证明其当前没有足够的资产来偿还。

Bars: The defence will fail if the defendant acted in
抗辩理由：如果被告行为属于以下情况，抗辩将失败

1) Bad Faith 1）恶意

(a) D had knowledge of the transfer being unjust (Lipkin Gorman).
(a) 被告知晓该转让是不公正的（Lipkin Gorman 案）。
(b) D was aware of a risk that the recipient was not entitled to the enrichment (South Tyneside MBC v Svenska International).
(b) 被告意识到受益人无权获得该利益的风险（South Tyneside MBC 诉 Svenska International 案）。
(c) D failed to act in a commercially acceptably way such as an inquiry of the payer (Niru Battery Manufacturing).
(c) D 未以商业上可接受的方式行事，例如未对付款人（Niru Battery Manufacturing）进行询问。
(d) Dishonesty. Considering the facts known by D, a reasonable person would consider their conduct to be dishonest (Ivey v Genting Casinos).
(d) 不诚实。考虑到 D 所知的事实，合理人会认为其行为是不诚实的（Ivey 诉 Genting Casinos 案）。

Vis-à-vis 相对于

In the UK, P must owe “duties and responsibilities” to D, which is a basis of complaining of D’s commercially unacceptable conduct (Juliet Bellis v Challinor).
在英国，P 必须对 D 负有“义务和责任”，这是对 D 商业上不可接受行为提出投诉的依据（Juliet Bellis 诉 Challinor 案）。
The Hong Kong courts in Arrow ECS have adopted a broader interpretation than the UK, meaning a breach of public regulatory statutes (like AML regulations) can constitute bad faith/wrongdoing, even if the conduct was not directed vis-à-vis the plaintiff.
香港法院在 Arrow ECS 案中采纳了比英国更广泛的解释，意味着违反公共监管法规（如反洗钱规定）可以构成恶意/不当行为，即使该行为并非针对原告。

2) Wrongdoing 2）不当行为

Any form of illegality constitutes wrongdoing and bars the change of position defence unless de minimis (Arrow ECS), and regulatory offences is sufficient (Pan Jing).
任何形式的违法行为均构成不当行为，并排除立场变更抗辩，除非属于微不足道（Arrow ECS），且监管违法行为即足够（潘静案）。

Ultra vires (Public Authority)
越权行为（公共权力机关）

A public authority cannot raise a change of position defence to retain taxes collected without legal authority (ultra vires), as doing so would stultify the high constitutional principle that the executive cannot levy taxes without clear statutory power (Test Claimants in the FII Group Litigation v RCC).
公共当局不能以立场变更抗辩来保留无合法授权（超越权限）征收的税款，因为这样做将削弱宪法上的重要原则，即行政机关不得在无明确法定权力的情况下征税（Test Claimants in the FII Group Litigation v RCC）。

D's commitment of funds to projects could be framed as a Change of Position defence. This would fail.
被告将资金投入项目可被视为立场变更抗辩，但此抗辩将不成立。

3. Estoppel : Requires 3. 禁止反言：要求

United Overseas Bank and Avon CC v Howlett
United Overseas Bank 与 Avon CC 诉 Howlett 案

1) a clear representation by the plaintiff
1) 原告的明确陈述
2) causal reliance by the defendant
2) 被告的因果依赖

But-for test 但为测试
一个重要的附加条件：被告的信赖必须是善意的。如果被告在收到利益时，自己已经知道或怀疑自己无权获得该利益，那么他就不能声称自己是“信赖”了原告的陈述

3) a detrimental change of circumstances
3) 不利的情况变化

核心原则：被告因信赖原告的陈述而采取了行动，从而使其处境变得更糟，或者说，如果现在允许原告推翻其原先的陈述，将会对被告造成实质性的损害或不公 (prejudice or detriment)

1. 积极地承担了新的义务或法律责任 (Incurring New Liabilities)
2. 消极地放弃了本可以获得的机会或利益 (Forgoing a Benefit or Opportunity)

禁止反言 (Estoppel) 和处境变更 (Change of Position)的区别

处境变更 (Change of Position) 是一个实质性的 (substantive) 抗辩，其目的是为了实现公平。它的效力是灵活的、可按比例的。被告只在他因信赖而实际改变处境的范围内受到保护
禁止反言 (Estoppel) 在传统上被视为一个证据规则 (rule of evidence)。它的效果是“一刀切”的，即“全有或全无” (all or nothing)。如果抗辩成功，法律就会“禁止”原告提出与其先前陈述相反的主张（即禁止他说“这笔钱是错付的”）

4. Limitation 4. 时效

D has raised the defence of limitation. The general limitation period for a claim in unjust enrichment is six years from the date the cause of action accrued (s.4, Limitation Ordinance). On its face, this would bar P's claim for any payments made before 20XX.
被告提出了时效抗辩。根据《时效条例》第 4 条，不当得利诉讼的一般时效期间为自权利主张发生之日起六年。表面上看，这将阻止原告对 20XX 年之前支付款项的主张。
However, P can rely on the postponement provision in s.26 of the Limitation Ordinance, which applies in cases of mistake.
然而，原告可以依赖《时效条例》第 26 条中的时效中止规定，该规定适用于错误情形。

Under s.26, the limitation period does not begin to run until the plaintiff "has discovered the...mistake...or could with reasonable diligence have discovered it."
根据第 26 条，时效期间自原告“发现该错误……或以合理勤勉本可发现该错误”之日起才开始计算。
The modern test for "discoverability" was established in Test Claimants in the FII Group Litigation v HMRC, where the UK Supreme Court held that time begins to run when the claimant recognised, or could with reasonable diligence have recognised, that a "worthwhile claim had arisen."
“可发现性”的现代标准确立于 Test Claimants in the FII Group Litigation 诉 HMRC 案中，英国最高法院裁定，时效开始计算的时间点为原告认识到，或通过合理勤勉本可认识到，“有价值的诉讼请求已产生”之时。

P’s argument would be that it could not have discovered the mistake with reasonable diligence before the CFA's judgment in June 2025. Before this, the law was understood to require the payment, and any legal challenge would have been speculative.
原告的论点是，在 2025 年 6 月 CFA 判决之前，原告无法通过合理勤勉发现该错误。在此之前，法律被理解为要求支付，任何法律挑战都属于推测性质。
D's stronger counter-argument would be that a "worthwhile claim" had already arisen in January 2025, when P's competitor, Chic Furnishings, launched its formal legal challenge. The commencement of litigation by a competitor on the exact same legal point is a powerful indicator that the settled understanding of the law is now contestable and that a claim is reasonably arguable and therefore "worthwhile".
被告更有力的反驳是，早在 2025 年 1 月，原告的竞争对手 Chic Furnishings 发起正式法律挑战时，“有价值的诉讼请求”已然产生。竞争对手就完全相同的法律问题提起诉讼，是一个强有力的指标，表明法律的既定理解现已可被质疑，诉讼请求具有合理争议性，因此是“有价值的”。
A court is likely to favour D's argument, finding that a reasonably diligent commercial entity in P's position could have discovered the potential claim when the litigation began. However, as the claim was brought in July 2025, it is still well within six years of January 2025. Therefore, the limitation defence is likely to fail for all payments.
法院可能会支持被告的论点，认定处于原告位置的一个合理勤勉的商业实体在诉讼开始时本可以发现潜在的索赔。然而，由于该索赔是在 2025 年 7 月提出的，仍然在 2025 年 1 月起算的六年期限内。因此，时效抗辩很可能对所有付款均不成立。

5. Ministerial Receipt: An agent has a defence if they have paid the money over to their principal in good faith.
5. 部门收款：如果代理人已善意将款项支付给其委托人，则其有抗辩权。

Transvaal and Delagoa Bay Investment Co Ltd
特兰斯瓦尔与德拉戈湾投资有限公司

Remedies (C12): After establishing a successful claim, the final step is to analyze what remedy the plaintiff can obtain.
救济（第 12 章）：在确立成功索赔后，最后一步是分析原告可以获得何种救济。

Basic Remedies: Restitution
基本救济：返还原物

P has a strong claim to a personal remedy for the restitution of the full HKD.
原告对返还全部港币享有强有力的个人救济请求权。

Should D’s defence fail, P’s primary remedy would be a personal claim for restitution to recover the payment.
若被告的抗辩失败，原告的主要救济将是提出个人返还请求以追回付款。

The basis for this remedy arises directly from the finding of an unjust enrichment, with the unjust factor being Total Failure of Consideration. The claim's objective is to reverse D’s enrichment, which became unjust once the contract was terminated and the bargained-for performance failed to materialise.
该救济的依据直接源自不当得利的认定，其中不当因素为对价完全失败。该请求的目的是撤销被告的不当得利，该得利在合同终止且约定的履行未能实现后变得不当。
Personal vs. Proprietary Remedies
人身救济与物权救济

Personal Remedy: A judgment for money against the defendant personally; the plaintiff is an unsecured creditor in the defendant's insolvency.
人身救济：针对被告个人的金钱判决；原告在被告破产时为无担保债权人。
Proprietary Remedy: A right in a specific asset (e.g., a trust, a lien), which has an absolute advantage in insolvency as the plaintiff can claim the asset directly or has priority.
物权救济：对特定资产（例如信托、留置权）享有权利，在破产中具有绝对优势，原告可以直接主张该资产或享有优先权。

Mistaken Payments & Constructive Trusts
错误支付与推定信托

The more difficult question is whether P can obtain a more powerful proprietary remedy in the form of a constructive trust over the money. The fact the money is held in a fund makes this a live issue. The availability of a proprietary remedy for a mistaken payment is uncertain. The old theory from Chase Manhattan that the payer "retains" an equitable interest has been rejected. The modern law is guided by the obiter dicta in two key cases:
更为复杂的问题是，原告是否可以通过对该笔款项设立构成信托的方式，获得更强有力的专属救济。该款项存放于基金中，使这一问题变得现实。对于错误支付是否可获得专属救济尚无定论。Chase Manhattan 的旧理论认为付款人“保留”衡平权益，已被否定。现代法律依据两起关键案件中的附带意见指导：

Chase Manhattan (Old Theory): Held that upon a mistaken payment, the payer "retains" an equitable interest and a trust arises automatically. This theory has been rejected.
Chase Manhattan（旧理论）：裁定在错误支付时，付款人“保留”衡平权益，信托自动产生。该理论已被否定。

1) Westdeutsche (Mainstream Obiter Dictum): Lord Browne-Wilkinson suggested a constructive trust may arise if two conditions are met:
1）Westdeutsche（主流附带意见）：Lord Browne-Wilkinson 提出，若满足两个条件，构成信托可能产生：

(i) the recipient has knowledge of the mistake, and
(i) 收款人知晓该错误，且

正例: The recipient is Zenith, a shell company. The knowledge of its director, who is the "directing mind and will" of the company, is legally attributed to the company itself. The facts state the director is part of the fraud scheme. Therefore, Zenith, through its director, knew from the moment of receipt that the HK$5 million payment was the proceeds of fraud and not a legitimate payment. Zenith knew it had no right to the money. Its conscience was affected from the outset.
正例：受领人是 Zenith，一家空壳公司。其董事作为公司的“指导思想和意志”，其知识在法律上归属于公司本身。事实陈述该董事参与了欺诈计划。因此，Zenith 通过其董事，从收到款项的那一刻起就知道这 500 万港元是欺诈所得，而非合法支付。Zenith 知道自己无权获得这笔钱。其良知从一开始就受到影响。

(ii) the property remains identifiable.
（二）财产仍可识别。

正例: The facts state that HK$4 million is "still sitting in Zenith's bank account." This is a specific, segregated fund that is clearly identifiable and can be the subject of a trust. This condition is satisfied.
正例：事实陈述有 400 万港元“仍存放在 Zenith 的银行账户中”。这是一个具体的、隔离的资金，明确可识别，可以作为信托的标的。此条件已满足。
反例: While the property here is identifiable in the segregated fund, the "knowledge" requirement is a major hurdle for P.
反例：虽然此处财产在隔离资金中可识别，但“知识”要求对原告来说是一个重大障碍。

At the time of receipt, D did not know the payments were mistaken; it genuinely believed it was entitled to them. Its conscience was not affected at a time when the property was identifiable. Knowledge would only arise after the court judgment, by which time the funds may have been mixed or dissipated. Therefore, on a strict application of the Westdeutsche test, a constructive trust would not arise.
在收款时，被告并不知道这些款项是错误支付的；其真诚地认为自己有权获得这些款项。在财产可识别的当时，其良知未受影响。知情仅会在法院判决后产生，而届时资金可能已被混合或挥霍。因此，严格按照 Westdeutsche 测试，构成信托不会产生。

2) Bailey v Angove's (Latest Obiter Dictum): Lord Sumption suggested an alternative basis: a trust might arise if the payment was made due to a "fundamental" mistake.
2) Bailey 诉 Angove 案（最新附带意见）：Sumption 勋爵提出了另一种依据：如果付款是由于“根本性”错误而作出，可能会产生信托。

反例: It is arguable that a mistake of law rendering a statutory payment invalid is "fundamental". However, this test is an uncertain obiter dictum with no clear definition or subsequent judicial support.
反例：可以争辩说，使法定付款无效的法律错误是“根本性”的。然而，该测试是不确定的附带意见，缺乏明确界定及后续司法支持。

Conclusion: 结论：

正例: Since both conditions from Westdeutsche—the existence of identifiable property and the recipient's knowledge of the mistake—were met simultaneously at the moment of receipt, a court is highly likely to find that a constructive trust arose over the funds at that point.
正例：由于 Westdeutsche 案中两个条件——可识别财产的存在以及受领人对错误的知情——在收款时刻同时满足，法院极有可能认定该资金自该时点起即产生了推定信托。

This conclusion is strongly supported by the established practice of the Hong Kong Court of First Instance. As noted in cases like Sultana Distribution Services Inc, the courts in Hong Kong have consistently applied the Westdeutsche principles in cyber-fraud cases to impose a constructive trust, providing an effective proprietary remedy for victims.
这一结论得到了香港原讼法院既定做法的有力支持。如 Sultana Distribution Services Inc 等案件所示，香港法院在网络诈骗案件中一贯适用 Westdeutsche 原则，设立推定信托，为受害人提供有效的财产救济。
Therefore, Apex has a very strong claim for a declaration that Zenith holds the remaining HK$4 million on a constructive trust for it, allowing Apex to recover the funds ahead of any other potential creditors of Zenith.
因此，Apex 有非常强的主张，要求宣告 Zenith 对剩余的 400 万港元负有推定信托责任，从而使 Apex 能够优先于 Zenith 的其他潜在债权人追回该款项。

反例: Given the high bar set by Westdeutsche and the uncertainty of the Bailey approach, it is highly unlikely that P could establish a proprietary remedy. Its claim will be confined to a personal remedy for the restitution of the HKD.
反例：鉴于 Westdeutsche 案设定的高门槛及 Bailey 方法的不确定性，P 极不可能确立财产救济。其主张将仅限于要求返还港币的个人救济。

Rescission (Contract) 撤销（合同）

An equitable remedy that renders a transaction void ab initio.
一种衡平救济，使交易自始无效。

Rescission is a specific equitable remedy that applies where a contract is rendered voidable due to a vitiating factor at its formation, such as mistake, duress, or undue influence.
撤销是一种特定的衡平救济，适用于因合同成立时存在瑕疵因素（如错误、胁迫或不当影响）而导致合同可撤销的情况。
Its effect is to treat the contract as void ab initio (as if it never existed). In this case, however, the contract between P and D was validly formed but was subsequently terminated at common law due to D’s repudiatory breach. The restitutionary claim is therefore a consequence of this termination, not a rescission of the original agreement. The effect is to order the return of the money, restoring P to the position she was in before the payment was made.
其效果是将合同视为自始无效（仿佛合同从未存在）。然而，在本案中，P 与 D 之间的合同有效成立，但随后因 D 的根本性违约而在普通法下被终止。因此，返还请求是该终止的结果，而非对原协议的撤销。其效果是命令返还款项，使 P 恢复至付款前的状态。

The Car v Caldwell case assumed that rescission has the proprietary effect of automatically revesting title, but this was an unargued assumption.
Car 诉 Caldwell 案假定撤销具有自动恢复所有权的财产权效力，但这是一个未经辩论的假设。

Remedies following Tracing
追踪后的救济措施

When P's property is transferred by X to D, the "tracing" process is used to establish the link in value between P and D.
当 P 的财产由 X 转移给 D 时，使用“追踪”程序来确立 P 与 D 之间的价值联系。

D receives property from a third party into which P can trace an interest, the property is the equivalent of P’s property in law, and D is treated as if he had received P’s property (Lipkin Gorman).
D 从第三方处接收 P 可以追踪权益的财产，该财产在法律上等同于 P 的财产，D 被视为已接收 P 的财产（Lipkin Gorman 案）。

After successful tracing, a plaintiff may elect to claim a proportionate share of the new asset (allowing for a share in any appreciation in value) or enforce a lien to secure the return of the original sum (Foskett v McKeown).
成功追踪后，原告可以选择主张新资产的按比例份额（包括任何增值部分）或执行留置权以确保返还原始金额（Foskett 诉 McKeown 案）。
老师对追踪 (Tracing) 这一工具的双重角色做出的一个极其重要的澄清：在不同情况下，追踪的功能和目的完全不同。

角色一：作为“建立索赔”的必要工具 (Necessary Tool to Establish a Claim)

适用场景: 主要是在不知情 (Ignorance) 和无权处分 (Want of Authority) 的案件中。
功能: 这些案件通常是三方关系 (P → X → D)，例如，P的财产被X（如小偷、越权的董事）转移给了D。在这里，P与D之间没有直接的价值转移，不满足ITC案的一般规则。
追踪的作用: “追踪”在这里是必不可少的法律过程。它允许P向法院证明：“虽然钱不是我直接给D的，但我可以一步步地证明，D现在手中持有的利益，其价值正来源于我最初失去的财产。” 追踪在这里的功能是
建立起P与D之间的法律联系，从而满足“以原告为代价”的要求，使得不当得利之诉得以成立。

角色二：作为“优化救济”的策略性选择 (Strategic Choice to Enhance a Remedy)

适用场景: 即使在典型的双方关系案件中，如错误支付 (Mistaken Payment)，追踪也可能非常重要。
功能: 在这种情况下，P直接付款给D，满足“以原告为代价”毫无困难，索赔从一开始就成立了。此时，“追踪”的功能不再是建立索赔，而是为了帮助P获得比普通个人索赔更强大的物权救济 (proprietary remedy)。
老师举的例子完美地说明了这种策略性选择：

情景(i) - 钱被花掉或损失: 如果收款人D破产或将钱挥霍一空，P的个人索赔将变得毫无价值。此时，P会希望通过追踪，在D的剩余财产中主张物权，以获得优先受偿地位。
情景(ii) - 资产增值: 如果D用错款买了一只股票，而该股票价值暴涨。如果P只提起个人索赔，他最多只能拿回错付的本金。但如果他通过追踪，他就可以根据 Foskett v McKeown 的原则，主张对升值后的股票享有按份所有权，从而获得资产增值带来的利润。这对他极为有利。
情景(iii) - 资产贬值: 如果D用错款买的股票暴跌。在这种情况下，P会明智地选择不去追踪。他会放弃对那堆不值钱的股票的物权主张，而是坚持其更宝贵的个人索赔权，要求D返还错付的、数额更高的原始本金。

Subrogation: Can allow a plaintiff to step into the shoes of a secured creditor; it is a remedy for unjust enrichment (Banque Financière).
代位权：允许原告代替有担保债权人的地位；这是一种不当得利的救济措施（Banque Financière 案）。

例句（抵押）: The court would revive SecureBank's first legal charge over Apartment B and grant it to Peter. This would allow Peter to enforce the security, for example, by forcing the sale of the apartment, to recover his HK$3 million ahead of any of David's other unsecured creditors.
例句（抵押）：法院将恢复 SecureBank 对 B 公寓的第一法定抵押权，并将其授予 Peter。这将允许 Peter 执行该担保，例如通过强制出售该公寓，以在 David 的其他无担保债权人之前收回其 300 万港元。

Lien: Can be used to secure a quantum meruit claim (Spencer v Frances).
留置权：可用于保障合理报酬请求（Spencer 诉 Frances 案）。