Excellent summation, Queenstromba, and ChaffinchofDoom's addition.
I'm also constantly checking these threads. I gave up on the Pprune thread a few days ago. I get more info, and sensible speculation here - thanks to Goldie and others. I think people, like Waswondering, should feel free to post a "marking place" post, because as we're now on thread 4 it's clear that we'll go on talking about this for as long we wish, and a few "marking place" posts won't make any difference.
I have been watching "Air Crash Investigations" on Sky, but only the last half - the first half is usually taken up with dramatisations of what was probably happening to the passengers and crew, and I don't want to watch that. But this evening's programme has made me wonder what the culture on the flight deck of Malaysian Airlines aircraft is like.
In a lot of places, the seniority of the captain is non-questionable, especially when senior pilots have a military background and their previous military rank follows them when they move to commercial flying. The last voice contact with ATC was from the first officer, which implies that the captain was the pilot flying. In many areas, the culture of seniority makes it difficult for the (more junior) first officer to comment, let alone intervene, if he thinks the captain isn't acting appropriately.
There have been a couple of those documentaries that I've watched, that have suggested that the captain (flying) has become disorientated, or has suffered a cardiovascular event, and the culture on the flight deck made it difficult, or impossible, for the first officer to take over. There is also the phenomenon of folie a deux, where two people in a close connection end up believing in something preposterous. Unfortunately, it'll need the recovery of the intact voice recorder to understand the interactions between the two pilots.
Apologies for the length of this post. If something matters to me, I can't help but write an essay. That's why I don't have a Twitter account.