I understand the going to far thing but it was me that was arrested I would simply say she attacked me and she never stopped resisting.
The video clearly shows Dawn trying to crawl out from under the other woman.
How could she be sure Dawn wasn't still trying to attack her.
Dawn's charging at her after she did get up pretty much proves that the woman didn't go to far.
Not in favor of violence but to arrest the person who was attacked is wrong.