If we're believing Flandrs' and AP's claims that means bluedoom didn't see the kill despite having a watch or that one of them carried out the kill in addition to their regular ability (which seems weird)
Though I do think it could be reasonable that in a game with two watchers Mafia has a way to avoid watches with the kill
Though I do think it could be reasonable that in a game with two watchers Mafia has a way to avoid watches with the kill