I still don't understand what was is motivation for this, and I assume he knew this lie would be very short lived...
One good reddit theory was that he was being investigated in Australia for tax evasion since he didn't have proof of a $54 million tax write-off in spending for his company. So, bitcoin and its anonymous transactions is the perfect cover.
Bitcoin isn't anonymous. What are you talking about? It's pseudonymous. You can track all transactions. That's so clearly not anonymous.
It was obvious from the start he isn't Satoshi. He's clearly got an ulterior motive.