All I know is she pushed him first while he was trying to do his job. That deserved a response whether that response was a punch, a taser, mace or a club doesn't matter that much.
Her being black matters, but it shouldn't. Unfortunately someone will raise a fuss about it. There is racism in this world, but I don't see it in this case.
Sure he probably has regrets. That doesn't mean he thinks he did something wrong or the majority of people think he did something wrong. He just regrets he is not in an winnable situation. I think the majority of people think he did the right thing. Unfortunately the minority of people yell the loudest.
I have never been accosted by a cop. Of course I have never back talked a cop, pushed a cop or resisted in any manner. Seems like an easy thing to do, but apparently it isn't. Who knew?