Sounds like BS to me. Did they say that things like this usually go on one's permanent record? To me, that would be ludicrous for something so minor to go on someone's permanent record.

I was a bit of a troublemaker in high school though, so take it with a grain of salt. I'm anti-authoritarian, as well. But, really. It sounds like you handled it well. Better than I would have, if I were a parent, most likely.