I never heard "why the hell where u hitting him" or nothing.
Because it's of no interest. You are not allowed to TA your teammates. If someone has done something bad to you, and you take justice into your own hands, you just turned him from an offender (who gets punished) to a victim (who does NOT get punished).
Someone else already said how to react. Write in chat to an admin, start a poll, take a screenshot, whatever. But don't strike back. Control yourself. Especially you, Punked, as the chatlog reveals you are an immature choleric.
P.S.: Heroin, please don't quote yourself in your signature. This is like jizzing on your own pic.