Right now Sam wasn't thinking about how Cas broke his mind and let the Leviathans loose. Right now he was just worried about how the man was gonna handle a punch like that. Sam had been on the receiving end on many of those punches and some of those had knocked him out cold. So when Cas just stood there and took it, he was amazed the angel turned human didn't fall to the floor unconscious.

He stepped into the room and gave the woman a short smile in return, looking back to his very, very pissed off brother. He was gonna say something, try to calm Dean down but... his head had enough problems and he really didn't want a concussion. That and yeah... maybe Cas did deserve a punch to the face... or a couple. But he'd let Dean handle that. After all... he did kinda stab Cas in the back when the angel took in Purgatory.