If you allow the government to put down a riot by harming rioters, no one’s rights are safe including yours.
So, in your scenario, riots cannot be put down by any means that have teeth.
So the riots, in short, cannot be put down.
Which means total anarchy: Murder, robbery, rape, arson, looting.
And you are okay with all that.
Society exists with mutually agreed upon norms of acceptable behavior. Burning homes, shops ,cars looting pillaging & plundering are NOT the accepted norms of behavior.
Refusing to force those engaged in those behaviors to cease & desist with all possible speed endangers society’s well being, force will be needed to stop the anti social behavior & the longer it takes to bring that force to bear the harder it will be to succeed. Also more force will be needed to restore order .
You do not treat cancer with gum drops you use chemo & radiation & sometimes even surgery for the purposes of amputation. The anti social behavior is metastasizing to other cities besides London because the Home Secretary refused to allow the police to do the needed work in the needed way.
In mob violence the folks doing the rioting have decided that for a while they don’t want to be civilized & that means as far as they are concerned the law of the jungle is in effect.
The longer that idea is allowed to run amok in the streets the greater the harm to the rest of civil society. Wishful thinking about reasoning with a violent mob is just that wishful thinking ! Trials/investigating committees/etc require that order in the streets be restored otherwise they don’t happen period.