That would be the store’s best defense unless he claimed that the onions needed to be removed because of an allergy.

To the restaurant, it’s just an oops mistake. I’ve very often seen cross-contamination at places which assemble your burger or sub. Those little trays that hold the onions, pickles, lettuce, etc. very often have contamination from one of the neighboring trays.

Also, if he has an allergy to onions, why not check the burger before eating it? It’s not like onions are a hidden ingredient.

This case seems like a nothing burger, tbh. 🤭

Is he reopening Jurassic Park? 🤭