Where did the shot come from?
That vehicle was surrounded. It's possible an officer from the other side saw someone crawling around and determined it was a threat or even a stray bullet.
Who was the officer on recording speaking with?
If I was directing a possible victim to safety and saw her go shot, I'd verbalize like that too even if the shot came from 100 yards away.
Did the officer communicate over radio that the passenger was out and moving to him?
If the person who shot percieved her as a threat and had no information contrary, they're likely more upset about this than any of us.
Was there even time to communicate effectively?
Was there any malice?
While I suspect the answer is absolutely no I cannot be certain. That said, if it wasn't malice it was a reaction of an officer in a very stressful situation. The kind of situation where the amygdala takes over for someone whether they know or not.
My biggest issue is that we live in a world where this happens and we don't logically evaluate rather than making snap emotional judgements. It leads to bad choices which mean lawyers direct agencies to not release video and full explanations when there's a mistake because well budget consequences.
Maybe tho, we need to stop with the 'gotcha' moments when mistakes happen. I've never met a perfect person who's made no mistakes. Demanding we over punish a good officer for one bad outcome when every day the officers life is on the line seems like an unhelpful choice to me.