The rule of res ipsa loquitur
A plaintiff may be relieved of the legal duty of proving the defendant’s negligence where the maxim res ipsa loquitur (the thing speaks for itself) applies. In such cases the negligence of the defendant is presumed and he must successfully rebut it in order to escape liability for negligence.
Requisites for res ipsa are:
i) The injury must have arisen from the person in control of the thing i.e. the defendant was in control
ii) There must be no clear explanation as why or how the injury occurred.
iii) The injury could not have arisen had it not been for negligence.
In Byrne v Boadle, the plaintiff brought an action in negligence alleging that, as he was walking past the defendant’s shop, a barrel of flour fell from a window above the shop and injured him. The defendant was a dealer in flour, but there was no evidence that the defendant or any of his servants were engaged in lowering the barrel of flour at the time. The defendant submitted that there was no evidence of negligence to go to the jury, but it was held that the occurrence was in itself evidence of negligence sufficient to entitle the jury to find for the plaintiff, in the absence of an explanation by the defendant.
The effects of res ipsa are that:
- It provides prima facie evidence on the part of the defendant
- It shifts the burden of proof from the plaintiff to the defendant and if the defendant’s explanation is credible the plaintiff loses the case