R v Smith  2 QB 35
The defendant was a soldier who stabbed one of his comrades during a fight in an army barracks. The victim was taken to receive medical attention, but whilst being carried to the hospital was dropped twice by those carrying him. Once at the hospital, he received negligent medical treatment; the medics failed to diagnose a puncture to his lung. The victim died of his injuries, and the defendant was charged with murder and convicted at first instance. The defendant appealed on the basis that the victim would have survived but for the negligence of those treating him. He also argued that his confession had been obtained under duress and was therefore inadmissible.
The issue was whether the negligence on the part of the doctors was capable of breaking the chain of causation between the defendant’s action in stabbing the victim, and his ultimate death.
The court held that the stab wound was an operating cause of the victim’s death; it did not matter that it was not the sole cause. In order to break the chain of causation, an event must be:
“…unwarrantable, a new cause which disturbs the sequence of events [and] can be described as either unreasonable or extraneous or extrinsic” (p. 43).
The chain of causation was not broken on the facts of this case.
With respect to the issue of duress, the court held that as the threat was made some time before the relevant confession and was no longer active at the time of the defendant’s statement, it did not render the evidence inadmissible. The conviction for murder was therefore upheld.