Good lessons learned all around.
Punk now realizes that not everyone is going to tolerate being bullied.
Son earns respect from fellow students and gained a bit of self confidence. After facing his punishment, he will be in a better position to decide if future encounters are worth the repercussions.

Unknown to us, at 12 years old, our son was being bullied by a 15 year old. On a Friday night at the local skating rink he shoved my son to the floor and called him a btch. Some friends helped him to a bench because his knee was hurt. Other kids came over and to tell him that Brad was going to kick his arse. My son wouldn't hurt a flea but he did have a few years of karate training. When Bradley came over and got in his face my son smashed his nose.
He told his mommy that he was just coming over to say he was sorry for bumping into him.
My son was found guilty of disorderly conduct and we got to pay the punk's medical bills.
We all learned that the justice system isn't always just. The magistrate was a smartass twaat. " now why would someone call you a female dog? That doesn't make sense. "