All this may indeed be possible. But modern aircraft are very well provided for when it comes to communications. Why didn't the Pilot send some kind of Mayday call ? Ordinary Mobiles probably wouldn't work at altitude, but most modern airliners now come with satellite-operated phones. Why did nobody try to use them to signal a problem ?
The only solution that I can see to this mystery is that some REALLY catastrophic happened to the plane. Perhaps it exploded in the air and blew to smithereens ?