With all that speculation, I'm wondering, couldn't the cause of the accident (if it was one) simply be a human glitch?
Of course pilots fail. For example, call on the wrong frequency, fail to turn on transponder, but that usually will be rectified.
This case is truly bizarre and baffles many experts. I'm sure by now many experts, beyond this forum, had contributed and brainstormed to figure out what could've happened and based on the probabilities and resources, chased those leads.