In the case Mustapha v Culligan of Canada Ltd., the plaintiff Mustapha had purchased bottled water from Culligan that contained dead flies. This image caused significant psychological harm leading Mustapha to develop a major depressive disorder that made it difficult for him to carry out everyday activities. However, his claim failed because although this extreme reaction was imaginable, it was not reasonably foreseeable.
The Supreme Court decision takes into account that if the defendant knew of these conditions, their plaintiff’s injury may have been reasonably foreseeable to the defendant but because there was no such evidence the damage was not reasonably foreseeable. Is this consistent with the eggshell rule in tort law, which states that a tortfeasor is liable for all consequences resulting from their negligence, even if the victim suffers an unusually high level of damage because of pre-existing conditions?