Referees chief Howard Webb has summoned all officials to a PGMOL meeting on Tuesday following high-profile VAR errors in the Premier League at the weekend.
Both Arsenal and Brighton suffered from decisions that were later described as "human error" by the refereeing body, with the Gunners conceding a goal to Brentford's Ivan Toney and Brighton seeing an effort from their left-back Pervis Estupinan disallowed at Crystal Palace.
Both games finished as 1-1 draws, with both Arsenal and Brighton dropping two points to dent their respective title and European place ambitions.
Chelsea were also incensed that they weren't awarded a late penalty for a handball by Tomas Soucek in their match at West Ham, another 1-1 draw, although that decision has been described as a 'subjective' one by the PGMOL.
In contrast, the Arsenal and Brighton decisions are being viewed as incorrect decisions by VAR operators Lee Mason and John Brooks, as the PGMOL explained in a statement.
"PGMOL can confirm its Chief Refereeing Officer Howard Webb has contacted both Arsenal and Brighton & Hove Albion to acknowledge and explain the significant errors in the VAR process in their respective Premier League fixtures on Saturday," they said.
"Both incidents, which were due to human error and related to the analysis of offside situations, are being thoroughly reviewed by PGMOL."
PGMOL representative Chris Foy explained Mason's error in the Arsenal vs Brentford match on Saturday night.
Speaking to the Mail Online, he said: "VAR was looking to see if there was an offside and whether Ethan Pinnock had blocked off Gabriel in the build-up. He looked at the possible foul and decided there hadn't been one and therefore referee Peter Bankes hadn't made a clear and obvious error.
"However, in the build-up to the goal, Christian Norgaard - whose cross Toney heads in - is in an offside position.
"However, the truth is that VAR didn't fully investigate with the lines. The lines, simply, didn't go down.
"And that counts as human error. Had the lines gone down the goal would have been disallowed for offside."
A Brighton club spokesman also confirmed that the PGMOL had apologised to them following the error for Estupinan's goal.
"As was confirmed to the club by PGMOL, a serious error was made in disallowing Pervis Estupinian's goal at Crystal Palace yesterday afternoon," they said on Sunday.
"The lines drawn in the VAR room to determine whether Pervis was in an offside position were drawn incorrectly, and the goal should have stood. While hugely disappointed by the error, the club's accepted PGMOL's apology and will not be making any further comment."
Webb has now summoned all officials to Stockley Park on Tuesday for a meeting to discuss just what went wrong, with one of his predecessors as referees' chief saying that he should dismiss Mason, who has made two similarly major errors in the past two seasons.
Hackett said on Twitter: “Howard Webb is now in charge of the PGMOL. One of the first things he should do is dismiss permanent VAR operator Lee Mason.
“This weekend, Mason lets another referee down by not disallowing the Brentford goal for offside. These are decisions that VAR should get right.”
Two years ago he was taken off VAR duties after overturning two red cards in a match between West Ham and Southampton, and earlier this season he disallowed a Newcastle goal against Crystal Palace which stood have stood.
