The ruling stresses that automatism is usually easily distinct from insanity, in the few cases where the lines are blurred it is a complex problem for prosecutors and mental health professionals.
He claimed that he had been acting involuntarily as a result of common hypoglycaemia of diabetics, induced by an over-generous insulin and he had not neutralised its effects with food, which made him violently aggressive.
Rather than risk the stigma of an acquittal on such grounds and a likely imposed treatment plan with loss of employment, the defendant changed his plea to guilty, got a conviction, and then appealed arguing he was not negligent in reaching a state of automatism whilst in a position of responsibility.
It follows in our judgment that Quick was entitled to have his defence of automatism left to the jury and that Mr. Justice Bridge's ruling as to the effect of the medical evidence called by him was wrong.
This case is critically contrasted by legal scholars[1] with R v Hennessy, where hyperglycaemia (an excess of blood sugar caused by not taking insulin) was considered by the court to be a disease of the mind under the M'Naghten rules.