He gets a good look at her, and while Dean doesn't underestimate women (he's had his ass kicked his his fair share of chicks), he doesn't immediately get the vibe that this one is a threat.

Not at the moment, anyway. Entirely possible she'll jump down and slit his throat, so he doesn't lower the gun, not completely.

"I'm not gonna hurt you." He frowns, glancing around at the carnage, then looks back up. "Are you okay? Did he kidnap you or something?" What a friggin' creep.