The result really doesn't matter.
He took a calculated gamble. He thought the chance that he could get a first down was higher than the chance of stopping the colts with 2 minutes and a time out. Considering that the colts had scored twice in less than 2 minutes (80 yard drive in 1:42, and 75 yard drive in 1:11), its a good shot, IMO.
He lost. That doesn't mean the decision was wrong.
The bad decision was throwing on 3rd down.