“It’s also entirely possible that there was a sensor malfunction that caused the flight computer to put the aircraft into a controlled descent.”
Give it a rest dude. The flight recorder says it was pilot commanded decent and the audio shows the other guy was pounding on the door. The way that door is designed the guy inside had to deliberately deny entry to the other pilot. Bu default it would not do it. 600 hours of flight is not ‘low time’ and he had several minutes to either figure it out or let the other guy it. There is no possible way your scenario happened.
Huh? The flight data recorder was recovered, but the memory card was apparently missing. There has been no data gleaned from it. How exactly did the FDR say the pilot commanded the aircraft to descend again? Please be specific. If there is anyone who needs to “give it a rest” it’s all the conspiracy theorists here who clearly want this to be a terrorist act.