It was a bandstand in the middle of a park, in the late evening/night time. There were no public order considerations and no indication of unrest. So the police could and should have held back, maintain safety and allow everyone to disburse naturally.
Of course there were some that were intent on causing trouble, but by going in and dragging away people in front of the media, for little more than passive noncompliance, was a bad decision. The Met have been here before, but it's much easier to maintain political and public support when you're steaming in against violent protesters, football fans, black youths etc than it is when you're dragging away a 5ft 2 woman who is there is solidarity for women in fear of attack from men.
I wouldn't be at all surprised to see heads roll, and maybe this will change the way all of us are treated by the police. I'd quite like to go to football games and be treated as a lawful decent member of society rather than being policed for what an exception small minority might do.