Disclaimer: This is an example of how one single random event can dramatically alter the course of a season. I acknowledge that the conclusion is built on a mountain of (very plausible) assumptions, which add up to an unlikely final result.
In the 2nd quarter of Indianapolis' week 3 game against Jacksonville, the Colts offense was driving at midfield, up 7 to 3. On 1st and 10, Peyton threw short right to Marvin Harrison. With the ball in the air Jags CB Rashean Mathis grabbed a handful of Marvin's jersey and used it to pull himself in front of Marvin for the interception. No flag was thrown and Mathis returned the pick 61 yards for a TD, making the score 10 to 7 Jags. Jacksonville would win that game on a last second field goal. 7 points off the board for the Jags likely would have been the difference.
Indy lost the division by one game and a tiebreaker that would have been reversed if Indy had beaten the Jags that game.
That would gave given Indy the #1 seed in the AFC playoffs and a first round bye.
They, instead of the Titans would have faced the Ravens, who Indy crushed in their regular season meeting.
Then they, instead of the Ravens would have faced the Steelers at home, who Indy beat on the road, for the AFC title
Then they, instead of the Steelers would have played the Cardinals, who the Steelers beat, in the Superbowl.
So, a missed call in week 3 cost Indy a Superbowl victory.
Disclaimer: This has been an example of how one single random event can dramatically alter the course of a season. I acknowledge that the conclusion is built on a mountain of (very plausible) assumptions which add up to an unlikely final result.