This person submitted a Yahoo bracket, but it wasn't part of the billion dollar challenge. But still, 32/32 is nothing to shrug at. The rest of his bracket is pretty reasonable too, except for Oregon in the final four. Oftentimes, people who are correct after the first sets of games are people who don't have a very sound bracket and randomly chose upsets that happened to end up correct.
Notice how he's not entered into the Quicken Loans Bracket Pool? They also sent out an email to all the participants stating that nobody was left perfect, so I'm going to guess that he either filled out his bracket post-Round of 64 or was unlucky enough to not actually enter it into the Billion Dollar Challenge.
I think he simply entered it into Yahoo Sports, but didn't actually submit it to the Quicken Billion Dollar Competition. If he were in the Quicken competition, the bracket page would have it listed under "Pools" - which its not. But I'm not 100% sure.