Yea, theymos said something about someone not being in the DT for long if they tag people for mere merit matters.
As stated above by Vod, given how the DT system works, theymos can't remove anyone from DT list.
Users cab ne removed from the DT list, only if other DT users make such decision.
I just did a search to see if theymos has ever said anything about giving negative feedback for abusing the merit system and I could found the following statement.
Giving negative trust for merit trading and deceptive alt-account use may be appropriate, but you should use a light touch so that people don't feel paranoid.