Proving this is relatively simple in a slip-and-fall or car crash case. If the owner of a store failed to clean up a wet floor and the plaintiff slipped and fell as a result, the owner was probably negligent. But victims of defective products rarely can find out exactly when and where the negligence occurred that led to their injuries.
In recognition of the fact that this level of specificity is simply not possible in most product liability claims, and that letting defendants off the hook for this reason goes against our sense of justice, there is the doctrine of res ipsa loquitur. This is a Latin phrase that means “the thing speaks for itself.”
In English, this means that the defect in the product could not exist unless someone acted negligently. In other words, the defendant is presumed to have been negligent until proven otherwise. Res ipsa loquitur shifts the burden of proof from the plaintiff to the defendant or defendants to show that there was no negligence.
This leaves the plaintiff with proving strict liability. He or she need not show that the defendant negligently designed or manufactured the product, but simply that the product was defective.
Despite not having to pinpoint the moment of negligence, proving product liability can be tricky. It takes an experienced attorney to make your best possible case and get a fair settlement or trial verdict.