20. No Challenge
The New England Patriots played the Kansas City Chiefs in 2020 and lost the game. However, there was one major officiating mistake that left viewers wondering why Bill Belichick didn’t issue a challenge. In short, he couldn’t. It looked like the Pats forced Patrick Mahomes to commit a turnover. But the officials saw it differently and ruled the play a sack.

This cost the Patriots their field position and of course, momentum. Furthermore, the Patriots were unable to challenge the decision because the referees called forward progress. This confused many viewers because they didn’t understand this rule. It made it all the more frustrating for them. In fairness, the Patriots weren’t amazing anyway, but they had some sense of moral high-ground.