Intentional or not, you cant hit with your helmet. Taylor MAys knows this. That hit was helmet to helmet, ignorance is no excuse. Dude should have been tossed. in the NFL you can bet that 'Hammer-Dropper' Goddell would have fined him.
I find it hard to believe that a 3 year player(at the time) wouldn't know the rules by then. or maybe he did know the rules, and knew that the 15yd penalty was worth the hit. Maybe he knew no coach on the sideline was going to discipline him.
I played organizaed football for quite a few years, my coaches would have kicked my ass if I hit someone like that.
*****off topic*****
why would a sure fire top10, maybe top5 pick (in last years draft) stay for his senior year, is it THAT good at USC???