I teach my kids to protect themselves and push back where needed, but I would NEVER teach them to hurt someone...regardless how bad it got. No room for that anywhere in sports...EVER! Pull them off the floor if you're going to result to that. Makes you and the entire program no better than the one that did it.
Life lessons is to be the bigger and better person. Don't let outside influences that you can't control influence you. Maintain self control.