P was arrested by the police, D, and injured himself by accident when trying to escape. CA held that the ex turpi causa defence applied. The police owed a person no duty to take reasonable care that P did not injure himself in a foreseeable escape attempt. P had caused himself injury while committing an illegal act.
Stuart-Smith LJ: The operation of the principle ex turpi causa non oritur actio arises where the claimant's claim is founded upon his own criminal or immoral act. The facts which give rise to the claim must be inextricably linked with the criminal activity. It is not sufficient if the criminal activity merely gives occasion for tortious conduct of the defendant. The principle is one of public policy, not for the benefit of the defendant. A crime punishable with imprisonment can generally be expected to lead to the application of the principle, and escaping from custody is sufficiently serious for the application of the maxim.