I'm not going to say much because some people who have been very kind advised me not to, but since this comment is on an already existing post...
He is in the wrong.
If this was a real fight, in the real world, then this fight never would have happened, he hides behind anonymity and only attacks the weak.
At least in the past he was also attacking haejin, I'm not sure if he's doing that any longer, but I do not consider haejin being weak. However I do see your point and I read the posts you made about this earlier.
You are of course free to do whatever you like, but I've had success in the past handling flaggers by leaving them to be and avoiding to continue the flagging with own actions.
You have been added to the @iflagtrash shitlist for spamming the network. Enjoy.