The official inserted himself into the proceedings at Wembley Stadium on Sunday early in the second half, when he awarded Juan Mata a goal on a shot in the 49th minute that didn't appear to cross the line.
A pair of Spurs players seemed to deflect the attempt away from the net, though the referee ultimately thought otherwise.
The final score—5-1 in favor of the Blues—hardly absolved the official of blame for the outcome. While Chelsea were clearly the better side, they were aided considerably by the commanding 2-0 advantage handed to them on the dreadful call. Had the play been assessed properly, Gareth Bale's 56th-minute rebound goal would've put Tottenham level.
Instead, Chelsea were able to maintain an advantage, which they rode to three more goals before the final whistle sounded.
Not that poor refereeing can necessarily account for a 16-8 advantage on shots by Chelsea, though the difference in the complexion of the game after the phantom goal accounted for at least of the shift in strategy.
In any case, it'll be Chelsea, not Tottenham, who will face Liverpool at Wembley on May 5th for the right to hoist the FA Cup.