Uh... leave her alone? Get rid of the people who are threatening, not the one doing nothing? Why should they use any force at all to remove someone who's broken no laws?
Sometimes you're the deadliest pragmatic asshole, sometimes you're really a naive buttercup, young Xant.
But thats because you're always defending an extreme viewpoint for the sake of being hardcore
"Getting rid of innocent person", a.k.a., moving from point A (where the innocent person might be hurt) to point B (where the innocent person is safe), is one of the many strange but real-life compromises law enforcement deal with on a daily basis.
The alternative would be either doing nothing to the point of escalation, or arresting ten times more guilty people that will pose ten times more problems.
No need to speak russian to understand that they did the most reasonable thing, especially if according to russian law she did "do something".
Then when you add all the particular background informations (Ukraine-Russia actual history + the body language of the people involved), its even more obvious that its business as usual that you could have seen in all the countries in the world.
TL;DR: nothing to see, move along.