Facts The defendant inflicted serious stab wounds on the deceased who, knowing she would be likely to die as a result, refused a blood transfusion because she was a Jehovah's Witness and accepting another's blood was against her religion. The defendant claimed that her refusal to accept the blood transfusion broke the chain of causation between his conduct and her death.
Extract There have been two cases in recent years which have some bearing on this topic: R v Jordan and R v Smith. In R v Jordan the Court of Criminal Appeal, after conviction, admitted some medical evidence which went to prove that the cause of death was not the blow relied on by the prosecution but abnormal medical treatment after admission to hospital. This case has been criticised but it was probably rightly decided on its facts. Before the abnormal treatment started the injury had almost healed. We share Lord Parker CJ's opinion ( 2 All ER at 198,  2 QB at 43) that R v Jordan should be regarded as a case decided on its own special facts and not as an authority relaxing the common law approach to causation.
In R v Smith the man who had been stabbed would probably not have died but for a series of mishaps. These mishaps were said to have broken the chain of causation. Lord Parker CJ, in the course of his judgment, commented as follows ( 2 All ER at 198,  2 QB at 42, 43):
'...if at the time of death the original wound is still an operating cause and a substantial cause, then the death can properly be said to be the result of the wound, albeit that some other cause of death is also operating. Only if it can be said that the original wounding is merely the setting in which another cause operates can it be said that the death does not result from the wound. Putting it in another way, only if the second cause is so overwhelming as to make the original wound merely part of the history can it be said that death does not flow from the wound.'
The physical cause of death in [the instant] case was the bleeding into the pleural cavity arising from the penetration of the lung. This had not been brought about by any decision made by the deceased girl but by the stab wound. Counsel for the appellant tried to overcome this line of reasoning by submitting that the jury should have been directed that if they thought the girl's decision not to have a blood transfusion was an unreasonable one, then the chain of causation would have been broken. At once the question arises - reasonable by whose standards? Those of Jehovah's Witnesses? Humanists? Roman Catholics? Protestants of Anglo-Saxon descent?
The man on the Clapham omnibus? But he might well be an admirer of Eleazar who suffered death rather than eat the flesh of swinef or of Sir Thomas Moore who, unlike nearly all his contemporaries, was unwilling to accept Henry VIII as Head of the Church in England. Those brought up in the Hebraic and Christian traditions would probably be reluctant to accept that these martyrs caused their own deaths.
As was pointed out to counsel for the appellant in the course of argument, two cases, each raising the same issue of reasonableness because of religious beliefs, could produce different verdicts depending on where the cases were tried. A jury drawn from Preston, sometimes said to be the most Catholic town in England, might have different views about martyrdom to one drawn from the inner suburbs of London.
Counsel for the appellant accepted that this might be so; it was, he said, inherent in trial by jury. It is not inherent in the common law as expounded by Sir Matthew Hale and Maule J. It has long been the policy of the law that those who use violence on other people must take their victims as they find them. This in our judgment means the whole man, not just the physical man. It does not lie in the mouth of the assailant to say that his victim's religious beliefs which inhibited him from accepting certain kinds of treatment were unreasonable. The question for decision is what caused her death.
The answer is the stab wound. The fact that the victim refused to stop this end coming about did not break the causal connection between the act and death. If a victim's personal representatives claim compensation for his death the concept of foreseeability can operate in favour of the wrongdoer in the assessment of such compensation; the wrong doer is entitled to expect his victim to mitigate his damage by accepting treatment of a normal kind: see Steele v R George & Co Ltd.As counsel for the Crown pointed out, the criminal law is concerned with the maintenance of law and order and the protection of the public generally. A policy of the common law applicable to the settlement of tortious liability between subjects may not be, and in our judgment is not, appropriate for the criminal law.
The issue of the cause of death in a trial for either murder or manslaughter is one of fact for the jury to decide. But if, as in this case, there is no conflict of evidence and all the jury has to do is to apply the law to the admitted facts, the judge is entitled to tell the jury what the result of that application will be. In this case the judge would have been entitled to have told the jury that the appellant's stab wound was an operative cause of death.