The doctrine of res ipsa loquitur should not be used where the judge has presented to him alternate versions of the facts and his job is to decide between them.
Lord Radcliffe said that an event which in the ordinary course of things is more likely than not to have been caused by negligence is by itself evidence of negligence.
Lord Normand said: ‘the fact that an omnibus leaves the roadway and so causes injury to a passenger or to someone on the pavement is evidence relevant to infer that the injury was caused by the negligence of the owner, so that, if nothing more were proved, it would be a sufficient finding of liability against him.’
As to the doctrine of res ipsa loquitur: ‘The maxim is no more than a rule of evidence affecting onus. It is based on commonsense, and its purpose is to enable justice to be done when the facts bearing on causation and on the care exercised by the defendant are at the outset unknown to the plaintiff and are or ought to be within the knowledge of the defendant.’
Judges: Lord Porter, Lord Radcliffe, Lord Normand
References:  AC 185,  1 All ER 392,  WN 95
- Barkway -v- South Wales Transport, CA, Appeal from, ( 1 KB 54,  1 All ER 392)