The thing is, your formula doesn't cover everything.
We all know that the Cowboys odds of winninig would have been greater with the TD vs. the FG. No one is or has disputed that.
But there are other factors - other variables. For example:
1. What would the Cowboys odds of winning be if we failed to make the TD (just a smidge above ZERO). Ther is a risk/reward factor, and while the reward would have been a greater chance to win, the risk was a certain loss.
2. How are the odds affected when you weigh the risk of placing eveything on one play - on Indy being able to win by executing ONE play, versus forcing Indy to execute a succession of plays just to get in range to make an attempt at a FG, which then is not guaranteed to be successful? What are the odds that an INT (an already proven element in the game), a dropped pass (as would take place by Wayne in OT), a penalty or other offensive misstep could have occurred that would have made it more difficult for the Colts?
3. How are the odds affected by the fact that Dallas had already been stopped by Indy on 6 straight plays from insided the 3 yard line?
4. How are the odds affected knowing Dallas has been a poor prforming redzone team for 2 years?
5. How are the odds affected knowing Manning had already thrown 3 picks in situations with less pressure than he would have at the end of the game?
6. How are the odds affected with Manning feeling the additional pressure of knowing that his running game had been conmpletely stuffed and everything had to be done through the air? How are the odds affected by the Cowboys also knowing this and being able to adjust their defense accordingly?
7. How are the odds affected knwong that the Colts are only a 7-6 team this season and are obviously not the juggernaut they once were, or that you still view them to be?