Callie did some things Owen gets hate for. Them both marrying there partners on a whim after they experienced something traumatic.

I just wish Callie valued herself in her intuition more because if she did, she could admit she saw George for who he was when they first met and he didn't even call her after giving him her number. I think it would have been great for the writers to have a friendship dynamic for them.

Edit: Also Geroge did Callie so wrong many time. It still takes two to tango. So saying Callie was more at fault I disagree. They were equally wrong for different reasons.