As long as he was awake for takeoff and landing there isn't even much of an issue. Up in the air planes generally stick to a certain flight path and maintain the same altitude with computers, Pilots are usually not awake for thentire duration of long-haul flights and take naps a lot of the way.
Still should be investigated though; pilots usually take their naps in the cockpit rather than business class, probably because of potential terrorist hijackings.