I think what caught him up was the undercarriage part. Then again, I'll never know what was going through the guy's head. I do know that the instructor who was in the plane with him was not paying attention, and as a result, is no longer a flight instructor, however he does still teach aerodynamics and air law. What I have heard though, is that a seminole going 85 kts with the gear up will slide pretty far on the ground, haha.
This gives me an idea for a new training aircraft. Build the belly of the airplane to be a big replacable skid that would take the brunt of a gear up landing, as many gear up landings result in further damage to bulkheads and total the plane. The prop and engine would have to be mounted high enough to avoid a prop strike.
Put a couple of lifting eyes to make recovery easy, just pick it up, drop the gear, and fly it again.