Pft! I'd get myself stuck in a physically-abusive relationship before Sam would. And I'm the kinda gal who, the first time I got hit, would either be out the door or he'd be picking up every one of his damn teeth.

Although, yeah, I can also see emotional abuse/manipulation as a possibility. But otherwise? Sam is far too strong, smart, and brave to get caught in a relationship like that. That's among the major reasons that I adore her. Hell, it's likely why Jack loves her too!