I can't speak for why he only has two negative ratings, since I was inactive when that event happened, but there is some justification for keeping him in DT. Being in DT is just as much about leaving good ratings as it is about being trustworthy oneself. Mexxer has tagged quite a few people that deserve it, so his historical ratings are still add value. On the whole he is also pretty inactive; he is not actively trying to trade, nor has he left any questionable feedback ratings since he scammed. I'd argue it's a situation similar to xetsr who also scammed and is inactive, yet is still in DT because he has left a lot of good feedback. Ideally though, these two users should be removed and have their ratings re-done by someone else in DT who is still considered trustworthy. It would just be quite a lengthy process, so no one has done it as of yet.