Rule: Is this still a valid reason to kill? It was a common sense kill based on the detective radar and the direction of the shots, a possible traitor being disguised in the area was just viewed as a case of the traitor tricking the innocents and was fair play. This isn't a rule anymore, it seems, it became relevant because I killed someone using it.
This is still indeed the case, providing it is of course impossible it was anyone else without a disguiser (no teleports in/out the area etc). This falls under common sense, hence there must be no other possibilities.