In a way, maybe you've earned the Winchesters' trust, and even... Dean's affection. Despite everything they've been through with demons, obviously they'd always have a back foot with you. You were always around, saving them from time to time, always able to do something. So you were in the bunker, and Dean was with you. You go out to get a beer and take the opportunity to look at everything, but surely the Kurds' knife would be with one of them. “What are you doing?” Says Dean.