Matt101
The last two posts of experienced rudeness are in my opinion not the fault of the crew but of BA and your fellow passengers.
How can you say that!!!! If a product is not available onboard or the crew have run out of cokes, surely the simple thing would be to suggest an alternative, NOT patronise passengers. Didn't they teach you that in Cranebank? They did when I was there in 1972.
If a passenger insults you for not providing what they want that is a different matter. I was taught there is always more than one way to skin a cat, and that line has proved so useful.