I'm a fan of his show and watch regularly and he's made numerous D&D references during the show and even made mention of G. Gygax passing. Growing up a lonely geek is part of the character he plays, though I wouldn't doubt he's had some personal experience too.
He's had a few other D&D references before. In two different segments, he mentioned manticores and centaurs, and the pictures accompanying both quotes were the respective monster from the 2ed Edition Monster Manual.
