With Chelsea up 1-0 after the first half of their FA Cup semifinal against Spurs, Juan Mata tried to slot the ball into a goal littered with bodies. Referee Martin Atkinson (who is going to Euro 2012 as a goal line assistant!) awarded the goal to put Chelsea up 2-0 in the 49th minute even though it clearly didn't cross the line (video here).
The grumbles for goal-line technology were immediate, but Spurs were finally ignited by the injustice and scored their only goal seven minutes later.
From there, Chelsea took total control, adding three more goals (including an excellent free kick from Frank Lampard and a lovely chip from Ramires to go with Didier Drogba's brilliant opener) and driving Spurs fans to leave Wembley en masse as Fernando Torres entered the match in the 84th minute. Hopefully Torres didn't take that personally.
The importance of Mata's goal that wasn't is, of course, debatable in game that ended 5-1. But at the very least it will serve as yet another reminder that officials need a failsafe and it probably shouldn't be another human being. A reminder we didn't need, but a reminder nonetheless.