Alternatively, we could just ask the host/gamemaster/however-you-want-to-call-them about that...
Even so, the reason agaisnt 13th is because of his Fool claim. I don't know what to think of him, since I get newbie vibes from him (changing opinions a lot, probably trying to stay alive at all costs to evade a mislynch, things like that), but even so he could be 50% Town or 50% Mafia.
I personally find Core a better target, since 13th doesn't seem as dangerous as he is. His motives to lynch 13th? It's because a Persuader isn't important, plus there's his Fool claim, so the Town wouldn't lose anything by lynching 13th.
There is no evidence that he is really scummy, all that's left is to pick on 13th's Fool claim (I don't understand, since his possible Fool victory wouldn't do anything bad to the Town, so where do some people see that he used this as an ace card in his sleeve to save his own ass?). I say that this vote is as ignorant as Blitz's, if the Fool is a harmless role that doesn't harm anything by winning.