I would argue, that this is an argument that the monopoly on force needs very good legitimizsation. Not a generalistic one. No every single use of force. Every single policeman should be investigated in front of law just the same way as a criminal, when harm was caused. And when it can not be seen as objectively proportional, police should become the same treaty by lawenforcement as everyone else.
Separation of power is the key, I would argue.