The defendant was a nurse in a mental hospital, charged with assaulting a patient. He claimed that he had been acting involuntarily as a result of diabetic hypoglycaemia due to excessive intake of insulin and not taking sufficient food after taking it,  which made him violently aggressive.

The trial judge ruled that this constituted insanity, not automatism. At appeal it was ruled that the trial judge was mistaken, and that diabetic hypoglycaemia was an induced by an external factor, and therefore gave rise to automatism, not insanity.

The Appeal Court did say, however, that if the hypoglycaemia were self-induced through negligence, it would not have been a defence. Lawton LJ, in his judgement:

'a self-induced incapacity will not excuse ... nor will one which could have been reasonably foreseen as a result of either doing or omitting to do something, for example, taking alcohol against medical advice after using certain prescribed drugs or failing to have regular meals while taking insulin.'