This implies intent.
> One pilot asked “why did you turn them off?” and the other said “I didn’t.”
To me this reads like an unintentional error with colossol implications.
Are you suggesting there was malicious intent and then a delibrately crafted denial by the perpetrator?
Pilots are drilled from day one that the fuel switches are sacred. After a few accidents where one engine failed and the pilot accidentally turned off the remaining functional engine, the training was overhauled so that it would be impossible for it to be an easy action done by mistake. One pilot is required to ask the other for confirmation before toggling the switch, I believe. It wouldn’t be something you’d do from muscle memory.
It easy to say that when you know there's likely no way to prove or disprove whether it as an accident or not. Unless a pilot left a note stating his future intentions, there's no way to determine their state of mind.
If there was no mechanical failure, the only remaining possibility is deliberate action. And if it was mechanical failure, we’d see an emergency air worthiness directive being issued, which we haven’t.