I recently went to an Indian restaurant with a friend. The friend ordered chicken chettinad. When it arrived, the friend smelled coconut in it. The waiter confirmed that, indeed, it had coconut in it (as apparently do many southern Indian dishes). The friend decided to send it back because he reviles coconut.
The friend explained that the menu had not mentioned coconut and argued that it is a "key ingredient" that should have been included in the description. I felt it was wrong to send it back. I argued that if there is a particular ingredient that he simply can't eat, he should always ask whether the dish contains that ingredient, much as one with a peanut allergy would ask, for instance, about the presence of peanuts.
Please, we need your help to resolve this. Was he right in sending it back?