If the last 4 minutes was missing and the aircraft came in very very hot, that could suggest that the black box stopped recording 10-15 miles from the airport.
Reports say no flaps, no spoilers for landing. The pilots had it pointed at the runway and it sounds like the aircraft went totally dead 10-15 miles from the airport.
Catastrophic failure in every system at the same time seems impossible.
How convenient that the last 4 minutes are missing.