They are finding largeish floating intact chunks of aluminum frame interor, which usually, but not always would be indicitive of it breaking up in mid air. The fuel slick would suggest it ddin't explode necessarily, though a bomb far enough back in the hold might not have ignited the tanks. No bomb threat or claims of responsability would tend to rule that out somewhat, but the lone nutjob theory is still available.
The timeline is what gets me. The Airbus A330 has 4 redundant electrical runs from the engine and battery banks to the cockpit and controls. All 4 follow different paths downt he fusalage, and you would have to cut all 4 at once to completely disable the electronics onboard. I might accept the radio being knocked out by a lightning strike to the radome, since the maintenance message system uses a different antenna, but that might have impacted at most communications systems. The 14 minutes from initial event to total cascading failure almost has to be a hull breach of some sort. Maybe an outer aluminum fairing strip tore away, exposing the runs to water and lightning strkes? sudden sheer draft broke the back partially and the crack just worsened over time? Partial fuel tank ignition somehow due to improper grounding that somehow managed to not ignite the other tanks? Was the pilot dumping fuel, and a strike ignited the stream and blew the tanks but didn't ignite the fuel that was already dumped?
Somethign odd happened here that should not have happened to a modern brand new jet liner. we need to figure out what that was.