My clues:
a) He lives in London. Satoshi's mining has been timezoned to indicate that he probably lived in the UK. The genesis block had a quote from The Times ("chancellor on brink of second bailout").
b) Wei is an expert C++ programmer, and the bitcoin client was written in C++
c) Wei created cryptopp, a C++ cryptographic library, so he definitely knew how to implement cryptographic features in C++. The bitcoin client heavily used the cryptopp library. The code seems similar too.
d) Wei Dai published 'b-money' system in 1998
e) 'British formatting in his written work implies Nakamoto is of British origin. However, he also sometimes used American spelling, which may indicate that he was intentionally trying (but failed) to mask his writing style, or that he is more than one person. ' - Bitcoin wiki