nick szabo is not satoshi. it has been investigated and accused atleast a dozen times. the only evidence people find is that parts of bitcoin is made using nicks theoris. but if you actually look at conversation history you will see that satoshi mentions nicks theory aswell as hal finneys theory and a few other peoples theory.

satoshi brought together many peoples theories into one seamless protocol. so just because 10% of code was inspired by nick, does not mean nick was satoshi.
give it 2 weeks and people will start accusing hal finney of being satoshi and say that hal's code was in bitcoin protocol and then speculate that hal's health decline was the cause of satoshi's disappearance.

then in 4 weeks time a guy named serius will be accused because he was one of the early guys that was playing with the code, accusing him of being satoshi and accidentally using his serius username when coding instead of satoshi username,.

it is weak investigation to grab at a single straw, it has been tried many times with smarter people trying to investigate the identity. yet many people cant even be bothered to search the forums to see the investigations have already occurred and dismissed certain people