Actually the game might not be over if there is a third party (though I guess the no killing besides mafia does exclude this).
Thing is I do find the spy interesting as a balance option, but ultimately, the mafia becomes a bit underpowered when used in such a short game (I'm assuming Vette and ST are indeed vanilla mafia here). I mean, if the cop gets a guilty result on one night... he's virtually protected by the watcher under penalty of instant defeat for the mafia...(a spy is not part of the mafia until recruited... well if gow used it that way). So we really had a mafia at 17% with a recruitable 3rd party (again, I'm assuming gow used the spy in the "usual" way). Then again, 3 mafia +spy would have been too much.
soo for the record, if the game goes on, my vote would be on wonk (we still have no inkling of his role).