But... I like her hair! There. I said it.
I know George was in a tough spot, but I think I would feel insecure in Callie's shoes. George just told her he wasn't ready to move in together, and now, once again, he is taking off to help Izzie. Not that there is anything wrong with that, she did need him, but from Callie's point of view, he is making it clear that she is not important enough to come first.