We really do not know why she pulled the other officer away.
I do not trust the press to give us the real story.
There’s video. She was standing off to the side looking pissed like she had just been ineffective and that Sergeant made her get out of the way so he could handle it. Then she RUNS a circle to get in behind him and grabs him.
Ten to one she was sucking and being ineffective, and when told to GTF out of the way, her little ego got hurt. So she turned rat.
“We really do not know why she pulled the other officer away.”
My opinion, based on my years as a correctional officer, is that she was probably trying to save him from making a very bad mistake. It will be interesting to see what kind of history he has.