Actually it's anything but flimsy.

Everyone in the mafia knows who everyone else in the mafia is. Citizens don't know jack about who the other citizens are.

So explain to me, why after you voted for Maxx Power, Manus and Resha suddenly, and directly after you changed their votes to match yours. "O WEL I TINK DANS INNOCENT". Yeah, my ass. You told them via either PM or instant messenger to change their votes you two-faced scum. If they had any common sense they would've waited a few posts to change their votes.

People don't just have epiphanies like that. "HOLY CHRIST MAXX POWER IS SUSPICIOUS CHANGE VOTE NOW PLOX." It doesn't work like that.