There are 2 things I would say about the tragedy of Henry Nowak. Firstly I genuinely think it is being misused / misinterpreted, as the incident itself has nothing to do with the current immigration issue which is so deeply affecting the nation. Instead it appears to be a simple case of a nasty, knife-obsessed individual murdering an innocent young man.
It is not that difficult to understand the initial attitude of the police when they were told they were being called to a racist incident. However, what it has exposed, and what I am surprised you don't acknowledge here, is that this guidance quite clearly states that it is fine for the police to treat people differently based on their ethnicity. And implicitly that it is fine for the police to treat the majority worse because of their lack of "protected characteristics". The same thinking pervades our society - discrimination is not only permitted but actively encouraged, most commonly against white men.
This is in a country which has led the world in terms of its acceptance of other cultures, ethnicities and ways of living, and as a result a lot of people like myself, who are part of the traditional majority, have had enough of the narrative that the country is racist and bigoted and with a shameful heritage. I and many like me are genuinely angry about what is going on. "Stop being divisive !" shout the left - well discriminating against the majority is the source of the division and the anger, not a solution to it.