Can't comment on the RAF, but flew the jumpseat in a USAF C-17 out of Ramstein and into Bagram a couple of years ago. It appeared the two pilots were being assessed by a third more senior crewman on the flight deck.
Being plugged into the comms, I heard this more senior fellow instruct a left turn shortly after departure, only for the plane to start banking right. "LEFT turn!!" he shouted. It didn't exactly fill me with confidence, especially in light of where we were heading...