Sorry if I'm being thick but I still don't know what this has to do with the colour of the trousers? The question of whether BA crew are responsible for the incident strikes me as totally unrelated to the trousers' colour.

Incidentally, I personally did not get the impression the OP said staff were incompetent. He resented them refilling his glass whilst he was asleep and even more so without a coaster. He may be right or wrong on that, but I don't see how the argument would differ depending on whether he was wearing white, denim, or pink leopard trousers - and that white trouser issue has been occupying much of the thread to date!