I think Bill Belichick has something to teach us. There are four things that can happen when we make a decision:
1) We make the wrong decision but get the right outcome
2) We make the wrong decision and get the wrong outcome (or the right outcome for that decision)
3) We make the right decision and get the right outcome
4) We make the right decision and the wrong outcome
Just because the outcome is wrong does not mean the decision was wrong. You can make the right decision and have a bad outcome, just as you can have a good outcome result from the wrong decision.
I personally think that he was right to go for it on 4th and 2 and all of the statistical indicators say that that decision gave him a better possibility for victory. What went wrong was not making sure that his receivers went far enough down field (although Moss was right there and was clearly in first down territory) and they got an absolutely terrible spot from the ref and there was no replay possible because they didn't have any timeouts left. (Those who argue that the MLB should be like the NFL who are said to be concerned about "getting it right" and use instant replay need to reconsider your position. As this play shows us, the NFL is not concerned about "getting it right" but only about having the appearance of getting it right.)
The Colts had just gone 79 yards in 1:40 on the previous drive, and the drive before that had also gone almost 80 yards in less than 2 minutes. What makes you think the defense was going to stop Manning all of a sudden? The truly radical move would have been to have let the Colts score immediately rather than trying to stop them in order to put the ball back in Brady's hands with two minutes remaining know he only had to get in field goal range.
We often judge things based on their outcomes, as is probably a good idea, but let us not forget that the outcome does not always mean the wrong decision was made.