When you’re working in a restaurant which deals with a wide variety of food ingredients and little ability to prevent cross-contamination how can you prevent customers from having an allergic reaction? And when the inevitable customer who has allergies eats food does have a severe reaction, can you be responsible for causing harm? In Canada, it entirely depends. The customer may decide to pursue damages under tort law and when this is done the plaintiff often succeeds. But if the injury is severe enough, say resulting in death or a coma, then those involved may be facing a charge of criminal negligence.