My gut is telling me SISTZ. There's a lot to ignore in order for him to seem townie. Apparently he's the rb, but apparently so was Nat, so he's more likely to be the scum rb. Tris has a check on him, his play has been weird, his posts have been weird, and he's omgusing Tris. I really think that's it and it really is the most obvious solution but our fear is causing us to doubt it.