I just rewatched this game. It really was a great Super Bowl overall.
I think the key turning point was late in the 2nd quarter.
We were up 12-3 and moving the ball with no problem at all. We then decide to punt the Ball on 4th and 2 from the Giants 45 yard line. I really think we should've just went for it at that point. We had all the momentum and we're moving the ball easily. If we score a touchdown on that drive we'd go up 19-3 and put the Giants away... IMO punting the ball there turned the momentum back to the Giants.