Her head felt like want to explode because of the problem that she had this day. She didn't think that it would be such a problem even though she knew by his face that it wouldn't be easy to talk with someone with a hothead.
Diana knew that it would be a problem she just didn't know that James would do that and said the thing that she thought James wouldn't say. It made her shocked and realized that there's still a lot of things that she didn't know about him.
She was glad that she could get away from that car and stay away from the bigger conflict even James seemed to cool down a little bit but in Diana's head, there's still some rage left in his heart so she decided to think about it.
It was also a good way for her because she was the one that felt the damage from his sharp words. She walked outside and back to the office. It wasn't the place that she wanted to go to because of the problem that she had but it was the only place that she could go.