Am I missing something?? Did you sell him something or buy something from him? If not, that could be classified as false feedback (bannable offense). Just looking out for ya bro, not saying what he did was right or justified.
I completely agree that it is very ngtg, but the itrader feedback system here is for deals done here. Since there was nothing bought or sold, I don't think it is legitimate feedback. At least by the forum rules. Again, I'm totally agreeing that what he did was ****ed up, I just don't want you to get banned because of it.