In general I agree. He's got plenty of bitcoins that aren't ID'd as Satoshi coins. Gavin going to the CIA is likely what caused him to withdraw. And he's probably still around here somewhere.

However, there is something to the Nick Szabo connection. Yet, Szabo himself appears to be possibly a pseudonym, so it's really hard to say. He may well have been a close follower of Szabo's work, and hid his tracks a bit that way. One standout word to me, which Satoshi used and is characteristic of a Japanese writing in English, is “ellided”. This isn't a commonly-known thing, but is apparent on use of Google n-grams, so it seems unlikely this would be a false clue. They did, however, both use the less-common term for hourglass ("sandglass"). So I am 50/50 on whether it's Szabo or an actual Japanese.