Well, “it works” in your desktop testing. That doesn’t mean it works. How do you test the permutations of 50 nested if statements such that you know “it works”? Whoops, there’s a bug reported from the field. Have fun debugging that corner case.

Or IOW, why do you think the static analyser flagged it in the first place?

It doesn't matter if it's 50 nested ifs or not if we're talking about a recent generation jet fighter - it's going to be hell to test no matter what. Even with provable control systems you're still at the mercy of cutting edge technology and the whole point of the jet is superiority over a yet unknown adversary with high tech capabilities so the system has be overengineered with that in mind.