The problem with Szabo is that nobody was able to locate any sort of code written by Szabo - ie, he doesn't seem to know how to program and the first version of Bitcoin is way beyond noob-level - crypto, GUI, distributed networking, ...
I suspect Hal Finney was behind the Satoshi handle on the original mailing list, and I wouldn't be surprised if he enlisted Szabo to help him write the paper since Szabo was also on that list, is a good writer, and Szabo's Bit Gold concept is pretty close to Bitcoin. But it's most likely Hal who invented Bitcoin's architecture and coded it up.