This.

There is no "correct" and effective action for a child to take against an abuser he's being exposed to by all the adults who should be expected to protect him from abusers. Consequently, he probably hit a pretty good point on the scale between "asking politely" and physical violence in a way that wasn't harmful to the victim (although of course it could be more harmful to some people in some situations, which is why it's obviously not okay as a rule).