I think what really had Maggie mad with Glenn was how he was trying to be angry for her, to assume he knew what had happened, that he knew how she had to have felt, that his outrage was almost more important than hers. He didn't ask how she was or what happened at the time, he assumed the worst and went overboard thinking he had to defend & take of Maggie cuz she couldn't take care of herself.
When she points out to Glenn that she took off her shirt etc because she was taking care of Glenn & protecting him, he seemed shocked - obviously he hadn't thought of it that way - which I think made her even madder.
At least that's how I took the situation.
