In this case, I don't think that it was fault of performing in school or not handling the heckler.
This was way to personal, I have been perfoming for some time now and I have never ever encountered a heckler that was this rude, and I have had the pleasure of performing magic for drunks, for boyfriends trying to impress their girlfirends with their "smartness" or just people that love to mess with your tricks and performances.
If this guy wasnt in the trick from the start and he suddenly jumps out into the middle and breaks your gimmick, Im pretty sure that he is pissed at you (and Im not talking about you being the center of attention.)
Im going to offer a piece of advice that nobody has given you here.
Go and talk with him, in a nice manner, and ask him why did he did those things, try to become friends with him (even if he is a jerk). Believe me, in the long run is worth the try.