Yes I too wonder if there is a back story here and there is more to it than meets the eye.
Yes, yes, let's search for excuses for the unlawful conduct of the poor little police officer.
You can see some police getting arsey with some people if they get the leglisation quoted at them.
Police culture has a very toxic "us vs the world" culture. That's why they consistently behave like such dickheads when challenged or when they have mentally categorised you as unworthy of police time, because they already view non-police as "less than" - so as soon as you stand up for yourself or ask for their time they feel entitled to put you back in your place.
Vulnerable people are used to the police abusing their power. It's just privileged people experiencing it for the first time now. The same people who wouldn't listen and didn't care when vulnerable people tried to speak about their experiences. And clearly still don't care.