Does it have to be a councillor though? I mean it's a broad assumption to believe that there is another corruption out there in the first place, but if so, could it not just as easily applied to someone else? As per my understanding, it wasn't a guarantee that one of the councillors was corrupt.
Also, if you were the one that was corrupt all along, it'd be a master stroke to play off everyone like this and have no councillors to stop you, lol.