Well, then . . .
You got paid, right? In that case, it doesn't much matter for you if the company went out of business, I guess. You did your best: the failure's on the executives who refused to listen.
Autodeception is far too common. I think that a tendency to lie to others and a tendency to lie to oneself are highly correlated, though. I generally find it's best to trust most those who are most honest with themselves, and trust everyone else not at all.