In the one real-life case I know of of cannibalism after a shipwreck (the Essex), the cabin-boy survived and wrote his account of what happened, and in fact later became a ship’s captain himself. Although, to be fair, the survivors’ boats were separated and the only boat where anyone was killed and eaten didn’t have the cabin boy on board.
The sailor who was killed, Owen Coffin, not only wasn’t the youngest on board his lifeboat (that was Charles Ramsdell, who actually suggested that they draw lots to kill and eat someone), he was the first cousin of the captain who was also on board.
