Wings Folded,
It's the flight crew, up the front, that must have different meals and that will always be adhered to, for the very reasons you have mentioned. I have to be honest and admit that I don't know if it is actually a requirement that cabin crew also have a selection of different meals. I should know that really, so will find out ASAP! However, we do always get a choice on long haul flights and there is usually someone on the crew willing to give up their choice of meal in the circumstances you describe. Either that, or you'd be amazed at how inventive we can be with combining different things. You wouldn't believe the number of passengers with serious dietary requirements that have, unknowingly, eaten a main from one cabin, served on a bed of starter from another, followed by a pudding from a third cabin. If it enables them to have something to eat, we'll do it! It is, however, all unofficial....