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.
I'm also interested in the earlier switch defects where the switches were installed with the locking mechanism disengaged on some 737s and inspection was advised for 787, but the incident aircraft was not inspected.
The airworthiness directive for that [1] indicates switches with locking disengaged should be replaced, but I wonder if it's possible to reingage the locking somehow, which could result in a situation where the locking wasn't engaged, the switches changed inadverdently and then when restored the run position the lock was engaged... that's a big reach, of course.
All that said, assuming the switch was working as designed, there's a semantic argument around deliberate and intentional. If the switch requires specific action, it's fair to call it deliberate action; but if the switcher thought they were activating a different switch, it's not murder.
Either way, there's no sense rushing to a conclusion of murder. Assuming one of the pilots activated the switch, they have already died and they are beyond the effects of human judgement; so we may as well wait for further information.
[1] https://ad.easa.europa.eu/blob/NM-18-33.pdf/SIB_NM-18-33_1