In the first half, the Saints D wasn't getting any pressure on Peyton and could hardly even slow the Colts down. The only thing that saved New Orleans in the 1st half was the offense holding the ball for nearly the entire second quarter.
Considering that, you're down 10-6 and your D is getting torched. You're about to give the colts the ball to start the 2nd half, Colt's get a field goal, at least, and you're only down a 7. Worst case, they get a TD and the game is practically over. Either way, you would have
had to score on the next drive to stay in it. Apparently, during the week, the Saints had seen something in the Colts kickoff coverage where the front line guys were backing off to far and to fast. Knowing that, your chances to recover a surprise onside probably go from 50% to maybe 70%. I take those
odds. I'd try to win the game over trying not to lose it.