It is possible that I don't know the mechanics correctly, but other players in this game also had the impression that if both DH and IM visit an alert Veteran, then both of them should die. Can someone with expertise clarify whether or not that is the expectation?

See Night 2 of following replay, when 5 (IM) and 10 (DH) visited 12 (Vet).
-Mafia- (4918).SC2Replay