I think he hits the $1000 clues first, so he has more to play with if he finds the Daily Double. It's a good strategy since the DD is rarely at the bottom.All the smart ones answer 90% correctly. It's the "start with the bottom row" that is unique AFAIK. Lots of contestants hunt for the DD. I can't recall one simply playing "in reverse".
And yes, when you do get to that DD, you have a lot more money than the typical DD hunter, and you bet big. As in all-in big.