It would be interesting to hear at what stage ATC knew there was a problem??
If total electrical failure would he lose everything including the radio??...if so he would be unable to advise ATC of his situation....Also total electrical failure ATC would have lost his transponder response but maybe still been able to see him on primary radar??...unsure at that height if that would have been possible.
How was the incident first reported??....was it by a call from the ship to the coastguard??
So many questions to be answered... but I guess in time, maybe certain questions will be answered but,unless the aircraft is ever recovered and I doubt it ever will be with the ferocious tides in that area I guess we will never know the full truth!!.