I think limiting the amount of times a player can purchase Detective in a given map (to 1 per map) would solve this issue.
I don't necessarily think it's the act of Detectives going into the T room that is upsetting people, I think it's more the fact that players (I am at fault and have done...
+1 a player I see quite a bit and can rely on to not cause any issues. This is a very well written application too which shows intent to take this seriously.