I think it's only natural for your daughter to stomp back, after 12 times.  I think she shows that she DOES know right and wrong since she didn't stomp back after the 1st time like some kids would.  Good for her! 

Probably the only other way she could have ended it better would have been to walk away and surround herself with other friends.  Then he would have had a harder time going after her.

I am surprised, however, that the teacher was gone wit no backup.  In my younger days, the teacher wouldn't leave the room unless another adult would come in and supervise for 5 minutes.