In the cases of food, it’s usually part of a severed finger after an unfortunate accident in the kitchen.
I’m not 100% sure on this, but I think it’s more likely an industrial accident that leads to the finger being included in some ingredient, which the restaurant misses. Not that accidents don’t happen in restaurants, but I can’t see a severed body part actually making it all the way to the customer without being stopped by the staff who witness (or experience) the accident. One would hope that’s the case in a plant as well, but I can see it being a lot harder to shut everything down and successfully find the body part in time inside a massive, automated factory putting out vastly more food.
