Area(s) of Law : Injury Law
Court : Court of Appeal
Source :  PIQR P 5;  LS Law Medical 70; 
Case Summary By : Robert Leonard
Causation – competing causes; whether to apportion in a case of successive injuries, some tortious, some not, with a pre-existing condition.
Robert Leonard of Hardwicke Building appeared for the successful claimant.
The Court of Appeal re-affirmed the conventional approach to causation that was appropriate for a single accident case, albeit one with complications. The defendant’s attempt to introduce principles of apportionment between competing causes, as applied in certain industrial disease cases, was rejected.
The claimant suffered an injury at work due to the negligence of the defendant. The injury accelerated by 10 years the onset of a pre-existing but asymptomatic back condition. A year after the injury at work he sustained an accidental, non-tortious, injury that aggravated matters. A further year later he fell downstairs when his back gave way and he sustained a significant knee injury.
The medical evidence showed that but for the injury at work he probably would not have fallen down the stairs two years later. It also showed that but for the injury at work the accidental injury the following year would probably not have caused him to fall downstairs.
However, written questions from the defendant to the jointly instructed orthopaedic surgeon also elicited answers to the effect that the cause of his current condition was 70% due to the pre-existing condition, 20% the accident at work and 10% the accidental fall a year later. The defendant’s case is that damages should be so apportioned and that the claimant should have only 20% of his losses.
The judge awarded the claimant 90% of his damages, finding that but for the injury at work the claimant would not have suffered the significant injuries thereafter. The deduction of 10% he attributed to the causative contribution made by the accidental fall.
The defendant appealed on the basis that the court should apply the approach seen in certain industrial disease cases (Holtby, Allen). The claimant cross-appealed against the reduction of the damages by 10%.
The defendant’s appeal was dismissed on the grounds that the judge had been correct to apply the standard ‘but for’ test to such circumstances where the evidence showed that but for the injury at work the damage would not have been suffered. The pre-existing condition was a classic example of the eggshell skull principle and was no ground for reducing damages. It was accordingly wrong to apportion damages in the manner urged by the defendant, particularly as the acceleration of the pre-existing condition had been factored into the calculation of future loss.
The claimant’s cross appeal was allowed on the grounds that the judge had been wrong to deduct 10% when the evidence showed that it was but for the injury at work, and not the later accidental fall, that the fall down the stairs would not have happened. The accidental fall was not a novus actus and there was no freestanding principle whereby damages could be reduced because of such an event.