And it's a horrible play call given their position on the field. If you're scared you can't stop Manning on a 60+ yard drive, why would you be any less scared at the possibility of giving it back to him with 28 yards to go? The reason it's dumb is because of where he made the play call, not the idea of trusting his offense more than his defense.
Seems like we are going in circles here. In my opinion, I don't think the Patriots defense could have stopped The Colts from marching down from anywhere on the field. I think he put more faith into his offense to pick up the three yards. If he felt his defense couldn't stop them from scoring from say the 60 yards out, I don't think he was expecting them to get the stop at the 20.
And again, I felt that had they simply let Addai run into the end zone with a minute something left, the Patriots would have gotten the ball back with one timeout, more then enough time to possibly get in field goal range.