Damn. I read his book years ago. I remember in the book, He says a shady friend got him into selling art on ebay and that he didn't know at first that the art had a fake signature. He said he only faked one signature and the story was picked up by CNN and people looked into his background.
Fake Forgery Lies eBay 1416948058 | eBay
He tries to justify his actions in the book. But he was being pretty shitty and I think he knew what he was doing.