I dunno about masons really. If there are more than one faction with KP, I guess town protective roles make more sense. I think the game is fairly heavy on PR though, if we accept Rhand's claim.
Only one kill: either one protective role, or both mafia killed the Rhand (no TMI, I have already designed a multiball, it's not reasonable to have 3KP, with so few players also). Or it's a cultist game. I think the 2 first options are equally probable. Much more than the third (but maybe it's just a wish I have)
If u want more mech speculation, I think it's a 12 v 2 v 2 v Rhand game.
I wouldn't be shocked to see a mafia roleblocker either, to add another option to the list. This does presume some kind of "designated killer" for the mafia teams as opposed to it being a team kill, but that's not unusual.