I have to say that on the basis of what Robinsonpyy says at least, the fault seems to be on the side of the airline. Motion sickness is not a new phenomenon, as witnessed by the presence of sick bags in front of every pax on every plane. Point taken about dehydration, but it is not difficult to quickly check if a pax is unfit to fly. But surely the burden should be on airline to demonstrate why this is the case? A second hand report from a F/A is not good enough - there would have to be something else.

And once a mistake had been seen to be made - well, this is where it got totally unacceptable.

No good EK - time to update guidance to staff and crew!