It's not like Allison is pre-determined of guilt. Personally, I'm dubious that she'll be punished severely if at all. But for the sake of the institution itself (which Allison has made a career out of undermining, it should be noted), Malus is going to do his level best to ensure that the Magistratum is thorough and fair. It might take awhile, but what's another week to (hopefully) silence both sides of the Allison Drama Club forever?