I'm trying to think up why AV actually does this as mafia. I guess he was in a somewhat bad spot and it could've given him a round of self-prez, in addition to causing the sheriff (or CDC) to counter-claim. It's just strange that he'd pick the PZ to give a green peek to. Maybe they aren't actually in contact yet??
It's possible he is a naive sheriff, but I really doubt that he'd be given a flavourless role. And a naive sheriff just seems inappropriately cruel to the town in a game without PMing.