Recovering money paid for an unlawful purpose (Patel v Mirza)

In Patel v Mirza the Supreme Court replaced the reliance test with a policy-based approach to illegality. Lord Toulson said the rationale is that it would be contrary to the public interest to enforce a claim if that would harm the integrity of the legal system. The court considers the underlying purpose of the prohibition transgressed, any other relevant public policy, and whether denying the claim would be a proportionate response to the illegality. On facts closely resembling these, the court held that a claimant who satisfies the ordinary requirements of a claim in unjust enrichment should not be debarred from enforcing it by reason only that the money was paid for an unlawful purpose. Dev was enriched by £25,000 at Ollie's expense, and the basis for the payment failed. Returning the money does not enforce the illegal bargain, so Ollie can recover it.

Why A is wrong: Patel v Mirza rejected the reliance test from Tinsley v Milligan in favour of the policy-based approach.

Why B is wrong: The purpose for which the money was paid wholly failed when no bets were placed; that is the basis of the unjust enrichment claim, not a bar to it.

Why D is wrong: The court rejected a rigid rule leaving the loss where it falls; whether to deny the claim depends on the policy factors and proportionality.

Why E is wrong: Claiming lost profits would enforce the illegal agreement itself; Ollie's claim is limited to restoring what he paid.