Maybe it's indicative of just how hardened Dean has become, but he doesn't expect Sam to stop him. He expects Sam to be sappy about it sure — expects him to lament a little, because that's just the way Dean remembers Sam as being, and he figures old habits die hard — but he doesn't anticipate that Sam will try and stop him. It doesn't help that Dean's guard is down, since he plans on dying anyway.

Sam is too quick. Dean is effectively subdued and knocked out.

When he wakes up, he's in the back of the van. He sits up, head pounding, and rubs his face. He doesn't know how long he's been out, but he isn't a Croat — yet.

He opens the door to the van and climbs out. He realizes, sparing a glance downward, that he is wearing Sam's clothes now. He doesn't have his pistol on him anymore, which makes him feel ill at ease. He never goes anywhere without having it available.

Seeing Sam, Dean walks over to him, noting that he's having a little trip down memory lane but not giving a damn about that — Dean is pissed.

"You fucking moron." Dean wants to go off on him, wants to punch him again, a few times for good measure, for saving him — because saving him risked Dean becoming something he never, ever wants to become.

But he needs to know, before anything else: "How long has it been?"