Premier League officials did not use the controversial 3D lines to check Son Heung-min’s goal in Tottenham Hotspur’s 2-1 defeat by Liverpool because they were “not required” due to the nature of the decision.
A Video Assistant Referee review left Spurs sweating on Son’s 33rd-minute equaliser, just seven minutes after Mohamed Salah put the home side in front at Anfield.
But a rather short-lived VAR check concluded that the goal was fit to stand as Son was onside at the point that Giovani Lo Celso played the South Korean through on goal where he expertly beat Alisson at his near post.
Liverpool defenders immediately raised their arms in the belief that Son was offside, but replays showed that he was level with Premier League debutant Rhys Williams. However, many questioned why the VAR review was completed without the use of the 3D lines that have come to drag out many onside/offside decisions since the VAR process was introduced, and that have led to decisions being made by the length of a toe or the location of an armpit.
The Professional Game Match Officials Board, who are responsible for making the decisions, explained that because Williams’s and Son’s left feet were the furthest-advanced points in deciding the offside line - and both were planted on the turf - officials did not need to check any other body part.
As a result, the VAR review was able to be completed in relatively short time - well under a minute - with referee Anthony Taylor able to award the goal and restart the match.
A PGMOL statement read: "The calibrated line was drawn from Liverpool defender Rhys Williams furthest point forward, his left foot, which showed that Son was behind him when the ball was played.
"As both players' feet were the furthest point forward and planted on the ground, 3D lines were not required."
Spurs had chances to win the game in the second half, with Steven Bergwijn twice played in by Son only to miss the target with his first effort and strike the far post with his second, before Harry Kane saw a close-range header miss the target.
The wasted chances allowed Roberto Firmino to head home Andy Robertson’s 90th-minute corner and secure a 2-1 victory that propelled Liverpool to the top of the Premier League at the expense of Spurs, but Mourinho was insistent afterwards that the better team on the day lost.
"I think even a draw would have left us not with the best taste because we had them there to win it," Mourinho said. "It was not just about the big chances, it was the moments of the big chances and the moment was when they were in trouble in their worst moment and we had it there to kill it but we missed it.
"We were in the face of the keeper two or three times and we just have to kill it.
"Bergwijn was face-to-face with the keeper twice, Harry was there with the header, we had it, we knew how to hurt them and we should do much more than we did.
"Normally in matches at this level you pay and I thought we would pay just taking a point but in the end we didn't even take a point so it is very disappointing.
"Sometimes you cannot play better than you did because of the opponent and I thought in such a difficult game against such a good team the boys were very good and we got punished."
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