She approached my car and told me, "I just wanted to let you know that Clay punched a girl in the face today."
She went on to explain that a girl had been bugging him by touching his arm (where he has a rug burn courtesy of big brother Austin. Don't ask.) According to his teacher, Clay did tell her to stop touching him several times, but the girl continued despite Clay's requests. When she did it again, he hauled off and smacked her.
I'm happy that the "use your words" and "if someone is bothering you, ask them to stop" lessons sunk in, but clearly I failed to follow up with the "if they won't listen to you, tell your teacher instead of slugging them" lesson. That has since been remedied. For good measure, I also added the "don't bite them, don't kick them, don't call them names, don't body slam them, don't trip them, don't grab their toy away from them, and don't spit on them" lessons for good measure. You know, because some kids (cough cough Austin and Clayton) like to exploit loopholes.