No, the bottom line is NO ONE knows what happened, period. For all you know, one of those wild-eyed conspiracists are right.
Go figure. Again, NO ONE including you knows what happened and for all anyone knows you're the wild eyed conspiracy theory guy with your rush to judgement that it wasn't a terrorist act.
Read the interview of the Boeing 777 pilot who obviously knows how that plane works. You’ll see what he says about the wild-eyed idea that the plane went up to that altitude to asphyxiate the passengers ... :-) ...