Hawk-Eye, which provides VAR technology to the FA and video to other sports, issued an apology that a "technical error led to an incorrect graphic being provided. To confirm, the VAR saw the correct image with the correct lines to make the decision. This was a case of the wrong image being provided to the broadcaster and we apologize.”
The decision did not affect the outcome of the game, but Manchester United manager Jose Mourinho could not resist the chance to weigh it.
"I'm familiar with what VAR is bringing that's good and bad," he said. "I think it's an experimental period. They have to get rid of the bad and make it perfect."
The problem is no one has ever suggested that VAR will be perfect.
VAR went relatively smoothly in MLS, which spent several years working on the project before its introduction in August 2017. But its use for league matches has been much more controversial in countries like Germany and Italy, where soccer is much more popular and every incident is scrutinized closely.
In a recent study of 804 competitive games in which VAR was used, the accuracy of decisions in the four reviewable categories went up from 93 percent to 98.9 percent. In only one in 20 matches was a clear and obvious mistake -- the standard for overturning a match-changing incident -- not detected since the introduction of VAR.
IFAB, soccer's rule-making body, is expected to approve the VAR system for the 2018 World Cup at its annual meeting of representatives from FIFA and the four British associations on March 2.
The test at the World Cup won't just be for the VAR crews to get calls right, but for those operating the world television feed to be provided the correct images upon which decisions are made.
What the World Cup can't afford is an errant squiggly line serving as fake news on a game-changing decision.