This is an outstanding post that shows first hand what life as an engineer is like. It is often very hard to truly come to a conclusion that is 100% correct, even given what seems like infinite resources to do testing and analysis.
The big take away from this is what it means to be a good engineer: to be able to bow your head, and admit you were wrong despite all prior evidence.
> what it means to be a good engineer: to be able to bow your head
No, I think being a good engineer means building good things. When the things get sufficiently complex, that starts to require control of your ego (what you described), being a good scientist/investigator, organizational skills, etc.
The big take away from this is what it means to be a good engineer: to be able to bow your head, and admit you were wrong despite all prior evidence.
outstanding!