I can’t answer that. My best guess, due to the volume of people outside and being understaffed as there were issues elsewhere
Unless there was violence/risk to life, it may have been safer to leave them especially given the numbers of officers injured in the last 48hours.
Not every incident can and will be treated the same. All circumstances differ.
When you say people are watching, I don’t know if you mean spectators to the above or just watching the police actions collectively in general but if it’s the latter, let them watch. Unless they are involved, and know the full story, their opinion on how they think things should be policed doesn’t really matter.