TC
Pertinent post as usual. Had thought of the Sabotage option, though that would still have needed to be effected somehow. Sudden pilot incapacitation from a gunshot? And you did indeed get me thinking about another S option too ....
After five days with no type grounding, emergency ADs or other maintenance advisory info, the cause options are probably fairly limited. It is surely hard to think of a mechanical failure cause that would not have precipitated some emergency action, even if just checking something.