I think we should lynch based off a parity argument. (Parity is even/oddness) As we have an odd number of people now, that means (assuming the mafia isn't blocked on any nighttime), every daytime we will have an odd number of people. Then, near the end of the game, it gives us a greater chance of winning, since the mafia must outnumber us, and may not have equal numbers as us. Thus, we should lynch to maintain this advantage, however slight it is. If we do not lynch, then the next day, although we may have slightly more information, we have a considerably greater risk of losing, as there exists a 4/6 chance of hitting an innocent. Should this happen, then we are guaranteed to lose, as the next day there would be 2 mafia and 2 innocents. Thus, in terms of statistics, I think we should lynch.
Therefore, I propose a lynch of Luigi, mostly due to his flawed analysis of the chances. Although it is true that on each respective day, those odds do appear daunting, in total, there is a chance of 3/7 of us being guaranteed to lose (3/5 x 5/7) this is significantly less than the 4/6 should we not lynch. So, he could have done this deliberately in an attempt to mislead us. However, even if he has not, I have no better reason to suspect anyone else.
Vote: Lynch Luigi#1