You're right about that. Other kids know and people talk.I dunno if you should really need notice that you're raising an asshole. You should be able to figure that out on your own.
I knew some parents who were proud that their kid was the tough kid who bullied other kids. And that includes mom, as well as dad.
Other teachers know, too. If you have a kid in your class with glasses and braces, they know if someone is giving them a hard time.
That kid looked like a sweet kid. He doesn't look like the type that would fight back (figuratively, even), unfortunately