I don't think these people have anything to complain about. The man that died was a drug dealer who was carrying a firearm at the time of the police operation. Only six police-involved shootings happened in 2016; police in the UK only fire shots during very difficult situations. Most officers do not even carry firearms here and our police are very well trained. There is no reason to protest after such an isolated, rare incident.
But did you bother to watch?