I think this bothered me the first time the episode aired, but I didn't figure it out till this viewing: how did we go from Dean's-gonna-kill-Sam to hey-five-hours-later-everything's fine? I mean, the only thing that changed was that the zombies left town. Please explain?
eta: okay,
luzmaria8 postulates that Dean probably wouldn't have killed Sam until Sam started exhibiting signs of zombieishness. So I guess they kept on waiting and waiting, and... waiting. yay. Okay, that makes sense.
In a related thought, I think much of this season can be summed up as: Dean and Sam get beat up by girls. Anyone have stats? Anyone? Bueller?