I have no specific knowledge of airplane systems, but I wonder if the airplane's computers could have been hacked to produce the disappearance? It would explain why so much effort would go into the planning, with the plane then appearing to be dumped in the indian ocean. The hacker would not have been on the plane, and the indian ocean is deep enough to make recovery and diagnosis of the hack difficult. It might explain how such a precisely timed sequence of events occurred.

I wonder if someone on HN has an understanding of what kind of safeguards go in to preventing a fly-by-wire system from being compromised. Presumably systems like communication, cabin pressure, navigation, etc are separated. Perhaps some of them are not software-based, and thus could not be compromised (but maybe their power could?)

It seems really unlikely, but so do most other theories.