In wouldn't rule it out. But I know from what I have seen in my town that the 2nd paragraph is true. If you attack the polo with a deadly weapon and run away they will give chase and shoot you in the back. They are trained to do this because "for all they know" you are a threat to the general public as well.
Discussion
It is best to keep the protests peaceful and if you are going to peacefully obstruct, stay cool and let them arrest you. Let them be the asshole.
Of you panic or strike them then you won't live to protest another day and you may hurt your own cause. Regardless of if the officer enjoys or regrets shooting you.
She did not have a weapon, the 3 shots were point bank at her face, the car only drove off like that because she was dead already
In the eyes of the officers her vehicle is a weapon. If she were standing in the street blocking traffic this would have played out differently. She is being detained and there is an agent I'm front of her car. It's possible she wasn't even looking where she was driving because of the two agents at her door.
She starts driving forward into the agent in front of her as he draws. He fires the first shot. Those are the events. The entire time they are ordering her to stop and the agent that fired was blocking her path.
I'm not saying it's right. No government authority is legitimate. There are plenty of criticisms to the approach they are taking.
Any armed police force would handle this situation this way. Protestors ought to be annoyingly peaceful. The Canadian truckers protest in Ottawa are the example IMHO.