"I am therefore not prepared to countenance the idea that all police officers should be tainted by the Sergeant Harveys of this world."

That's precisely what you did - "I don't think this was an isolated incident. I think that Sergeant Harvey, and a lot more of his ilk, regularly use such techniques because they are too lazy or too callous or too stupid to adhere to properly laid down procedures."

My underlining, but your words. Blatant stereotyping, and seemingly acceptable in your view, yet you (apparently) give people who stereotype muslims and black people a 'flea in their ears'.

If what you really meant was, "I think that Sergeant Harvey may have used such techniques on other occasions, and it may be that there are others who do likewise", I'd probably have to agree, but I also believe that we need to see much more than the short, one-sided clip of one incident to make the kind of blanket judgment that you've made.

And with regard to the issue of the offender 'howling in agony', most people are capable of 'howling in agony' to order - I certainly could if necessary - and without any actual pain being felt whatsoever. It's called 'taking the piss'.

I have a couple of close relatives who are police officers - one here, one in Canada - and they could regale you for hours with anecdotes about the unbelievable and outrageous behaviour towards the police of individuals and groups they come across in the course of their work. Many of them make the incident in question seem very insignificant indeed, and it seems that the most important requisite for a police officer is to have the patience of a saint.