Interesting that this thread has come up as I flew back from Dubai last week and was sitting in one of the 2 seats right at the back of the 777. One of the crew members luggage was in the overhead to my left and not long before landing he had to move my bags out which were in from of his case to access his case. I then witnessed him putting a few bottles of water into his case.
I did wonder whether this was in order but as others have pointed out it would seem all was OK.