Why did Peyton Manning refuse to shake hands after loss?

After his last throw of the game, Peyton Manning left the field with his helmet still on without stopping to congratulate the winning quarterback or anyone else who would be wearing a 2010 Superbowl ring.

Why? Manning alludes that it was the Saints' moment to relish with each other. I think that's a cop-out. they showed his pained expression several times late in the game before the Colts' last-ditch effort. It wasn't a look of confidence, but a look of pain, as if Manning couldn't believe this was happening. You could tell from that expression that he had already given up before his last set of downs.

He used the word disappointing over and over. But what was truely disappointing, I think, is the lack of sportsmanship. Every kid in youth sports has to go through the line and shake hands afterward - no excuses, no exceptions. Not that pro ball players need to do that every game, but at least do it after the biggest American sporting event of the year. At least do it for the millions of families that are watching. 

But not Manning. It's OK to be disappointed. But it's not OK to walk off the field like that.

Anyone care to disagree? Please share the other side to this debate....