Masks were advised. There's no way people should be hassled by police over something advisory.
Do we know what the conversation was? I don't see why the Police shouldn't advise, e.g. a polite "Excuse me, is there a reason why you're not wearing a face covering?" / "Sorry, Officer, but I find they make it hard for me to breathe" / "OK, fair enough, though you might want to try some different ones to see if different types help as they really are to everyone's benefit.", rather than "Excuse me, is there a reason why you're not wearing a face covering?" / "F*** off, the law doesn't require me to so I won't if I choose not to" / <escalation>?
Because wearing one is for the benefit of others, this really is a case of responsibilities over rights, which is difficult for some to comprehend. Keep the exceptions for people who have real problems with them for medical reasons (including severe autism, so not just physical), don't go looking for them just because you don't like masks. I don't either, but I'd rather wear one than have it on my conscience that I didn't take a minor inconvenience on the chin (ha!) to prevent someone else potentially dying.
Very often (though not always), cases of staff or Police "being unreasonable" are because of failure of the attitude test.
In that case it's highly likely that they have touched the same surface and then touched their face.
Possibly a hymn book, prayer cushion or something.