Hmmmm... have you patched the game ? Ive always had that encounter the same way, first talk to the Merry Fools, then the Maulers appear and become hostile (all of them) after talking to the leader, then my party and the Merry Fools (mainly my party
) bash the Maulers.
Oh, and the bartender becomes hostile too, at least it has always happened to me, dunno why