Giving food to another student can be dangerous. What if that student is allergic to that food? Since the school is in loco parentis, they are considered responsible for making sure the allergic kid DOESN’T die. Some well-meaning kid on the sly could cause the school to suddenly have a death via negligence lawsuit (it has an official name that escapes me) to deal with.

Trust me, I’ve seen zero tolerance applied to far dumber situations than this. I’ve seen zero tolerance used as an excuse to not have to judge a case on individual merits, because the staff involved were STUPID and couldn’t be counted on to judge a singing contest. We’re talking “I don’t care if we never handed you a rulebook, ignorance of obscure rules isn’t an excuse.”