That really stinks. I do civil war reenacting with the 150th NY, I know a few guys from the 124, but cant say i Know that kid. In any case back when I was in 10th grade I believe it was, 9 years ago or so, I did a demo for my class and no one was concerned when i walked in with my 1863 springfield. Times have changed eh?
The reproductions are capable of hurting people though. The powder charge is enough to give you a really bad burn, and even the wadding can cause harm if it hits you soon after leaving the bbl. They are also Fully Funtional in that you CAN fire live ammo out of them. I've done it, and the results are impressive. .58 cal is pretty big and it makes a nasty entry/exit wound.
I dont think this kid was a threat though, best he can probably do is shoot 3 rounds a minute and charge bayonette HUUURRAAHHH.