Who: The IOC
Olympics: Barcelona 1992

Canadian Sylvie Frechette entered as the favorite in synchronized swimming, but was given a low 8.7 score from a Brazilian judge in the technical section of the event. The judge claimed to have entered the wrong score accidentally, but the rules did not allow for a correction. Largely because of the scoring error, Frechette finished the competition second to American Kristin Babb-Sprague. A lengthy appeal process resulted in Frechette receiving a gold medal over a year later in October of 1993. Babb-Sprague was allowed to keep her medal so there are two gold medal winners from the event. Way to go, technology!