They were violating a mask mandate They were asked to leave and were then trespassing. (Not criminal trespassing yet because that requires reporting them to the police and then they would have to come back) Police are the front lines of law enforcement and and are given the first call on enforcement judgement calls. The shop keeper getting too close and violating personal space was not deemed assault... the violent shove of the shopkeeper was deemed assault. From that point on everything the shopkeeper did was 'self defense'. You may not agree with the calls the responding officer made but unfortunately he does have the power and authority to make those calls as he sees fit. The only recourse is to take it up with the courts at that point.