Calciopoli, a.k.a Numerous Greedy Italians (2006)
The interesting aspect of a referee's job is that without featuring for either team in a match, they can still have be the most important factor in determining a result. A sending-off, disallowed goal or even an offside can radically alter the course of a game, and set one team down the path to victory and the other to despair. However, despite all the head-scratching decisions previously seen and the heartache and anger that they can cause, one must sit back and reflect on the fact that these are professionals that just made a mistake. That is unless you were a football fan in Italy in the mid-2000s, in which case your cries of "we were robbed" could be more accurate than usual. The scandal that gripped Italian football in 2006 dragged its name through the mud and tore their league structure to shreds. And a number of referees were not above becoming involved in the disgraceful activity of match-fixing. And why not? They had the perfect position to conduct such a heinous crime. Current and former referees such as Tulio Lanese, Massimo De Santis and Gianluca Paparesta were indicted in the scandal for acting in a favourable manner towards particular teams and accepting hefty bribes from clubs such as Juventus, Milan and Fiorentina. This led to extremely heavy fines and jail sentences for many involved, and led to the relegation of Juventus from Serie A. The relegation and points deductions had the greater repercussions of the loss of numerous great players from Italian leagues and dropping the quality of the division to a point that it has yet to fully recover from. Whilst in the prior moments of refereeing madness, they have been mistakes. Horrendous, mind-boggling mistakes. But, in this case, we can have no sympathy for these referees that deliberately took their national game and tarnished its honesty for their own financial gain, and so this is the most awful refereeing mistake.