Personally I don't think we can say 100% either way, who here can actually say this has happened and who here can guarantee it has not.

Whatever the truth is, I think this behaviour is disgusting and I would absolutely report the crew immediately.

IME there are terrible pax and terrible crew, but the vast majority of people are not like this. I have seen BA crew deal with some quite frankly revolting pax in the past, far beyond the point at which I would have told them to f-off. What those cabin crew have subsequently done behind the curtain I don't know, and guessing isn't terribly productive.