If no one else said it, she was wearing a bandana over her face a lot and as I’m sure all know, she had a weighted glove. The guy might not have even known he was hitting a girl.
Also, per the pictures in the daily mail, some long haired guy who was aside Damigo, got busted and bloodied in the head, maybe that was from one of the bottles thrown? If someone does that to someone on your side, you might be more agressive, the adrenaline is running high. She was wearing both a cap and bandana over her face. Again, one might not know that was a female.
http://www.dailymail.co.uk/news/article-4418540/Supremacist-caught-video-punching-woman-face.html