I think for once Bellicheck was outcoached. No adjustments for the rush on offense, a tough matchup on the D line and the Giants defense was on fire. Pats also had a good effort to hold them to 17 (with the old bend not break deal) but ... just not enough!
Still and all, if you look at the successful teams this year, most had great offenses and a passing game. Old axioms like "establishing the run" and "focus on defense" weren't enough. Eli engineered some great 4th quarter comebacks, without which the Gmen wouldn't have made the playoffs. As it was they got hot at the right time and won it!
The other point is that defenses didn't score any points in the SB, meaning the offenses had to get it done when they needed to.