I am not sold on the idea that, ....Hal Finney wasn't Satoshi ...    I think a group of people with one spokesperson was responsible for the development of this experiment and then Hal Finney a member of this group, died. They were all part of the Cypherpunks back in the day, so you might find them if you knew who was behind those people using those Bulletin boards back then. 

The Bitcoin protocol is actually a combination of several different concepts and I think many people shared their expertise and knowledge of these different concepts and combined it into one.

Hal Finney might have stored the Private keys to the million some odd coins, but it is lost now.