I say roast the guy. He'd never come here to apologize if he didn't know he was busted, and this apology seems quite insincere to me. I'm also wondering how many of his other pieces are his own and not someone else's.
Who is going to say no to that? Would you forgive him if he said yes? Its fun asking rhetorical questions. Of course he'd never come here if he wasn't busted, but the fact is he was busted. And people learn from their mistakes. At least smart ones anyway :) Now he'll either really stop doing it, or learn to use an alias…