Sometimes the statistically correct decision still leads to a bad outcome.
If you convert 50% of your 4th and short opportunities in FG range, and then score TDs instead of FGs, over time you net about 7 points for every 6 points kicking. That's a simplification and doesn't factor in yardage or missed kicks/failures to score the TD or PAT, but the point is that a coach making a correct statistical decision will only be judged by the outcome, regardless of his understanding of odds. There are too many variables to calculate the exact odds for every decision over the course of a game, but the strategy should be to play odds in your favor.