LEGAL PRINCIPLE: TORT LAW — Negligence — Res Ipsa Loquitur — When Doctrine Applies and Its Evidentiary Effect
PRINCIPLE STATEMENT
Res ipsa loquitur is not a rule of law but describes evidence from which negligence may be inferred. It is a rule of evidence affecting onus, based on common sense, enabling justice when facts are unknown to plaintiff but known to defendant. Plaintiff cannot rely on it where a possible non-negligent cause exists.
RATIO DECIDENDI (SOURCE)
Per Ejiwunmi, JSC, in Royal Ade Nigeria Ltd. & Anor v. National Oil and Chemical Marketing Company Plc (2004) NLC-32000(SC) at p. 10; Paras A–C.
"The maxim is not a rule of law; it merely describes a state of the evidence from which it was proper to draw an inference of negligence. It is 'no more than a rule of evidence affecting onus.' It is based on common-sense, 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 with the knowledge of the defendant. However, a plaintiff cannot rely on the maxim to create a presumption of negligence where there is no evidence of negligence but there exists a possible non-negligent cause of the injury."
EXPLANATION / SCOPE
Res ipsa loquitur is an evidentiary rule, not a rule of law, allowing inference of negligence. It applies when facts are within defendant’s knowledge and plaintiff lacks access. The principle applies to tort law and negligence. The rule enables justice where plaintiff cannot prove specific negligence. Plaintiff cannot invoke it where a non-negligent cause is possible. The inference is permissive, not mandatory.
