Engineers rule! (TaMoDee, BS, MS, 45 years on the job in the field, etc etc.)
I disagree, but assuming you are correct, I would expect some Apple engineer to fiddle around and then claim the device is unlocked. If FBI doesn't have the assets to unlock the device, how would it know it wasn't unlocked?
It would know because it wouldn't be able to unlock other devices it held. No, I suspect FBI just wants a piece of Apple's proprietary work. Apple should tell the court that work is fairly priced at $380B.