I think you will find the lack of police response in situations like that has a lot more to do with the police not willing to get involved in any such situation than a race thing
From experience I know police will often take their time to attend something like a pub brawl regardless of who is involved, hoping that if they take their time the brawl will be over when they get their and they can just arrest who ever is standing.
far better option in the view of many in the police force than trying to break up the fight something many of them are not physically capable of doing
