Glad to see that the nut was found .... was following but had nothing to add that wasn't already said.
Once finished the lower intake installation keep a good eye on your oil level and quality. An oil change is warranted anyway to ensure that no coolant ended up down there after the lower intake came off. But its equally important to ensure that you didn't muck up the seal procedure when putting it back together. Its easy to get coolant leaking internally and not notice it right away .... until you throw a rod or lose a main.
This advise is is born from experience. I had the lower intake gasket replaced by the dealer last week. They blew my engine and are replacing it right now because of incompetance that resulted from a lack of checks as I described above. I'd be very cautious until you are sure things are solid.
Cheers and best of luck