Bristow v Barts and the London NHS Trust

In a personal injury claim, causation must be established on the balance of probabilities. A claimant’s sincere belief about the cause of an accident does not establish causation where the belief is founded on hearsay, rumour or an unreliable account. The court must assess credibility broadly, considering truthfulness, perception, memory, subsequent influence, motive and the inherent probability of the account. Where reliable eyewitness evidence and the surrounding circumstances support an alternative explanation, the claim will fail if the claimant cannot prove that the defendant’s breach caused the injury.

The claimant, a consultant anaesthetist, sought damages after collapsing in an operating theatre. He had no recollection of the accident and alleged that he had been struck by a theatre light moved by a nurse. The defendant accepted potential vicarious liability if that account were proved, but contended that the claimant had slipped on Betadine disinfectant which had spilled on the floor.

The court considered the theatre footage, incident report, pre-action correspondence, witness evidence and the claimant’s account. The central issues were the cause of the fall and whether it resulted from any breach of duty by the defendant.

1. Claim dismissed. The claimant failed to establish on the balance of probabilities that he was struck by a theatre light or that any act or omission of the defendant caused his injuries.
2. The theatre footage showed that movement of the light was mechanically possible, but the alleged sequence was highly unlikely. There was no evidence that the lights were defective or unsuitable.
3. The incident report and pre-action letter did not provide reliable evidence of causation. They were based on an assumption recorded by a nurse who had not seen the alleged impact, and that assumption had been repeated and embellished through hearsay and rumour.
4. The court accepted the evidence of the theatre nurses that Betadine routinely spilled during preparation and that the claimant slipped on his own spillage while moving the instrument trolley. The absence of any need to move the theatre lights at that stage, the claimant’s lack of head-injury treatment and his subsequent activities supported that conclusion.
5. In assessing credibility, the court applied the guidance discussed in the dissenting speech of Lord Pearce in Onassis v Vergottis [1968] 2 Lloyds Rep 403. Sincerity was not decisive. The assessment included memory, unconscious bias, wishful thinking, motive and the inherent probability of the evidence.
6. As the accident was caused by the claimant slipping on Betadine, rather than by any negligent act of the defendant, the claim was dismissed.