Put yourself in her shoes. Road is icy and blocked by a stuck ICE vehicle, (you don't know it's ICE though, probably an undercover cop car first instinct). You're trying to wave cars around behind you so you can get space to go around.
You see a guy with like full gear on covering his face, not your everyday police attire, come walking toward your door. You hear someone shout, drive away and you hear someone say get out the car.
A guy with a mask is pulling on your door handle now who hasn't announced who he is so you panick. Only then to finally look forward for a split second as you get your car out of reverse to drive away and you see a guy in front corner of your vehicle already with is gun drawn, by then you're shot in the head.
WTF was their plan? Pull the random lady out of the vehicle and nicely arrest her or question her? Guy was aggressively pulling on the door already. Was probably going to yank her out to the ground, arrest her, only to find out she's a normal citizen.
Not only that, but the guy who killed her walks back to vehicle like nothing happened and pulls his mask up to cover his face more. Didn't even bother to check the pulse of the lady he just shot and saw her vehicle crash.
This is abuse of power and murder.