Was he working any ATC unit ( London information maybe) at the time and able to get out a Mayday call?? It amazes me how many folk choose not to talk to any ATC unit whilst flying over water or hostile terrain. I have had three instances in the past few years where aircraft have called Mayday on my frequency Scottish Information......in every case we had a rescue helicopter airborne before thankfully the aircraft had force landed safely......the service is there so beggars belief why at times some people choose not to use it.