Re: Manning walking off the field. This is something that is also completely overanalyzed by the media, particularly in the last 5 years. The only incident that was classless was Belichick refusing to shake another head coach's hand after losing a few years ago. LeBron walking off the court after losing to Orlando last year and Peyton Manning are both non-stories.
I agree, Goom. As far as a classless act to match Belichick's, I have to go way back to the Pistons in '91, when the Bulls finally got past them. Not only wouldn't they shake hands with Jordan, Pippen and company, they started to walk off the court while there was still time left on the clock.
The strange thing is that their coach, Chuck Daly, was one of the all-time class guys in the history of the NBA (a nifty dresser, too). But Isiah, Salley, Dumars, Laimbeer, Rodman, et al. displayed one of the single greatest showings of poor sportsmanship that I ever recall in a "Big Four" sporting event.