Referee Keith Stroud has said sorry to Newcastle United after he "misapplied the law" by disallowing Matt Ritchie's penalty against Burton Albion.
As the Magpies scored the referee blew his whistle and award a free kick to Albion.
But the rules state the penalty kick should be retaken in this situation.
The refereeing body Professional Game Match Officials Limited said: "Keith and his team are understandably upset and apologise for the mistake."
Luckily for Newcastle, Ritchie went on to score anyway and they won 1-0.
But it started us thinking about the rules of the beautiful game and whether we could do any better than the referees.