I disagree: it could have happened in many Western countries.
The problem with a 'it's political correctness gone mad!' argument is it ignores the context in which those laws were enacted. Racism and sexism were systematic and endemic in the UK during much of the 20th century.
You say that "political correctness had taken hold in local government by the early 1980s", but you don't mention that the reason for this was that during the early 1980s there were numerous serious race riots throughout the UK.
Hate speech and anti-discrimination laws have drastically improved the lives of millions of people in the UK. I don't pretend that discrimination has been eliminated, but you simply can't deny the fact that British society today is considerably less racist and sexist than it was thirty years ago.
Now, there is a side effect to this. Because the UK doesn't have explicit free speech protection mistakes have been made enforcing those laws. Sometimes people mis-interpret them, in the same way people mis-understand health and safety laws. But I would argue these costs are far out-weighed by the benefit that a ethnically diverse and accepting society has brought. I see that since I started typing this someone has already replied to you saying how much their life has improved due to these laws.
Getting back to your original point: I don't think this is a UK specific problem. I could probably cherry-pick similar examples from the US and other EU countries and come up with equally compelling arguments that "this shambles could only happen in [X]".
This is obviously a very emotional topic for many people. I don't expect this reply to change your mind, and I fully expect people to disagree with me. All I really want to get at is that as someone who also lives in the UK I disagree with your viewpoint.