I think the cops are absolved of any blame for this one.
They are damned for doing nothing and would have been damned for wading in with sticks.
Actually, they go 'wading in with sticks' they potentially face a personal assault charge and being sacked. They do nothing the force gets slammed, not the individuals.
Not to mention they were hideously out numbered.
There's a time and a place for both. If only they'd get it right.
They cops were so outnumbered here that they were correct in not arresting anyone at the time. What use is arresting someone when that, in itself, removes 2 cops from the situation as they deal with the arrestee thereby leaving their colleagues even more understaffed....
Arresting these people as it happens is the easy option, not always the smart option...
- which tbh, not much has happened yet