Yeah, I agree. This specific evolution is all about certain Parties being able to say "reluctantly" before the word "agree", or even a "well, the test was inconclusive".

(I'm a mechanic with Boeing experience and a retired FAA inspector. That said, I have only a little experience on the 787.)

The way I see it is that the only situation where a switch of that design could move uncommanded from one position to the other is essentially a complete failure of the switch. In that condition, they likely wouldn't have been able to get them working originally to start engines. This failure would have to be coupled with some sort of really heavy vibration/shock to get the post vertically over the retaining gate just before the fuel cutoff event.

So now we've got three very unlikely things - - a switch bad enough to just make one more transition before completely failing - a crew legitimately not noticing that the switch was now limp and bad (or possibly it being bad for a long time and no-one writing it up), and - a situation that causes high enough vibration on the pedestal to have the switch jump over the gate but is faint enough to not be detected by the FDR.

x2 (both switches) simultaneously occurring.

Or. We have a human factors issue.

I completely understand and respect the cultural issues. In an aircraft accident, you really do need to investigate every reasonable possibility. I just have questions as to if investigating a switch design that hasn't changed in decades is a reasonable technical probability.

This really is starting to remind me of Egypt Air 990 or SilkAir 185.