Williams v The Bermuda Hospitals Board
The law as to causation and material contribution has now been reviewed by the Privy Council in the case of Williams v The Bermuda Hospitals Board  UKPC 4 but this has not perhaps brought the clarity that was hoped for.
The facts of this case involved delay in the diagnosis and treatment of appendicitis following the patient, Mr Williams, attending hospital. Mr Williams suffered a perforated appendix which caused sepsis and in turn damage to his lungs and heart which progressed to myocardial ischemia. The evidence was that the injuries were developing as the sepsis progressed. The first instance decision in the case was that the delay in treatment was negligent (there should have been earlier diagnosis of the appendicitis and treatment by surgery) but that it could not be proven, on the balance of probabilities, that it had caused all of Mr Williams’ injuries. Accordingly, the ‘but for’ test was not satisfied – i.e. ‘but for’ the negligence the injury would not have occurred. The Court of Appeal (Bermuda) did not agree and found that the correct consideration was not whether the delay caused the injuries in their totality but whether the delay ‘materially contributed’ to the injuries. They concluded that it did.
A further appeal led the matter to be considered by the Privy Council which decided that the Court of Appeal was correct. They found that where there are cumulative causes for injuries, successive events are capable each of making a contribution to the subsequent outcome. The case of Bonnington Castings v Wardlaw  A.C. 613 was directly applied such that it was found that the injury (myocardial ischaemia) was caused by sepsis, some of which was attributable to the negligent delay and some of which had already begun irrespective of the delay. Accordingly, the injury was ‘indivisible’. It was considered that the development of the sepsis and the damage caused to the heart and lungs was a ‘single continuous process’. The period of delay was found to have ‘materially contributed’ to the injuries.
The Court of Appeal had of course considered causation in the case of Bailey v Ministry of Defence  where it was suggested that in certain circumstances the usual ‘but for’ test could be modified. In Bailey the issue was that there were two causes of the claimant’s weakened condition which led to her injury, one being the result of negligence, the other not. It was enough that the negligent cause had ‘materially contributed’ to the injuries.
Bailey was felt by many to have left questions in the law of causation unanswered and that clarification could have been provided by the Privy Council in Williams. The Privy Council commented, obiter, that Bailey did not involve a departure from the ‘but-for’ test. In that case the totality of the Claimant’s weakened condition was the cause of the injury. The fact that there was a non-negligent cause of the weakened condition must be looked upon as taking a claimant as you find them.
However, despite these comments, the Privy Council seems to have endorsed the position in Bailey. It appears now that following Williams, if negligence contributed to the injuries sustained (as opposed to being the cause of them, as in Bailey) then the doctrine of material contribution applies and the claimant succeeds. The doctrine will not apply if the injuries are divisible and the cause of each is attributable. Accordingly, going forward it looks as though the divisibility of injuries will be key as to whether the test of material contribution can be applied.
In my view, clarity in respect of the application of the doctrine of material contribution is still required.