Bull's head snaps up when he hears the far too familiar voice and he runs for the widow. He is on the second floor and he can see what is going on. He doesn't think about what he is doing but rather flings himself out the window as the moose pass by the alleyway below him, aiming to straddle the beast and maybe steer it away from Krem.

What he doesn't take into consideration is that moose are not built for having a large Qunari crash into them, to be honest very few things are, and the poor beast crumbles to the ground under him. "Krem!"