No way that was an accident it seems.
Though it might ,depending if that women was trying to push back from getting back into the room then stopped and all that force that the cop used to push her send her flying.
I've learned that from experience when a friend of mine was trying to get me to do something and I was pushing back refusing to go forward while he was push me,then I just stop using some force and I fall forward.
Try it. And you'll know what I mean.
Ever since then if someone is joking around and pushing me ,while I push back, I have a fear of getting hurt by stopping to to push back.
It's hard to say if that happened in the video.