I've wondered if the "hard turn" was a deliberate action or maybe something they did while suffering the effects of hypoxia? Flygirl mentioned before that one of the first symptoms is euphoria, so is it at all possible the cabin lost air pressure and incapacitated them and either a passenger made the turn after finding them passed out (without knowing how to use the comm system) or the pilots did it without realizing? Or maybe they made the turn on purpose but weren't fully cognizant of why or where they were going? Is it possible one of them did it and didn't even understand why?
This question is mostly for Flygirl, by the way, but obviously anyone can answer. I know no one here is an expert, though.