I would say that the item about W.Yorks if it is true, is very much the exception. I've been in the business for over 6 years and have found 99% in the Police Aviation business in UK to be very open to visitors, both pilots and policemen. We welcome people and have numerous visits from all types although we try and discourage potential customers of ours.
Maybe you caught W.Yorks at a bad time, they probably have loads of requests from all and sundry to see their new aircraft.