At 0-0 and with the Reds a man down, Liverpool winger Diaz’s goal was ruled out following an unusually quick video assistant referee (VAR) check by Darren England, in which the customary offside line graphic was not shown.
“PGMOL acknowledge a significant human error occurred,” the statement read. “PGMOL will conduct a full review.”
It continued: “The goal by Luiz Diaz was disallowed for offside by the on-field team of match officials. This was a clear and obvious factual error and should have resulted in the goal being awarded through VAR intervention, however, the VAR failed to intervene.”
BBC Sport understands the correct procedure was followed for the controversial decision but the mistake was down to human error.
The lines were drawn in accordance with normal procedure and every other aspect was checked.
However, what is being described by sources as a lapse of concentration led to a loss of focus around the initial on-field decision and then a ‘check complete’ being confirmed rather than an intervention which would have resulted in the goal being awarded.
It is understood referees’ chief Howard Webb has spoken to Liverpool this evening.
The Reds also had Curtis Jones and Diogo Jota sent off, and lost to a stoppage-time Joel Matip own goal after resolutely keeping Spurs out.
Speaking after the match, Jurgen Klopp said his side’s defeat came in “the most unfair circumstances” with “crazy decisions”.
“That is not offside when you see it,” he told Sky Sports.
“The ball is between Mo [Salah]’s legs, they drew the line wrong and didn’t judge the moment when Mo passed the ball right.”
‘This will put so much doubt into decisions’
Former England striker Alan Shearer described VAR’s error as “incomprehensible” on BBC Match of the Day.
“The one bit of VAR we have accepted and learnt we can’t argue about was offside,” he said.
“This will put so much doubt into decisions that go on. It is a monumental error, we spotted it straight away.
“We are led to believe Darren England, the VAR, and Daniel Cook, the assistant VAR, have done all they should have done in terms of drawing lines but, instead of saying ‘goal’ for some reason had a huge lapse and said ‘check complete’.
“What is the point in having an assistant VAR? It was 30-35 seconds between that and allowing kick-off. The VAR had a momentary lapse, but why can’t the assistant VAR say we need to stop this?”A horrendous day for the officials and VAR. We have seen some howlers but that is the biggest. Trust is going to be a big thing going forward.”