[McGruff]

I wonder if a highly skilled programer would always have the same belief.

I was going to make a joke about the plane doing a Windows Update but decided not to, at least publicly.

In the interest of full disclosure, I are a somewhat skilled programer. This override check would be caught during certification testing. if not, someone's head would have rolled. Maybe I shouldn't use that phrase either.

[null and void]

This override check would be caught during certification testing.

Unless it was an "after market" addition.

We've been known to add "upgrades" to Iranian SCADA controls on centrifuges.

No particular reason a sufficiently skilled and evil actor can't "upgrade" flight software.

But I do agree, that the factory software is as fail-safe as any human agency can make it.