Misleading graphics showing seemingly wobbly grid lines were displayed by broadcasters in the immediate aftermath, with Mata’s strike eventually correctly ruled out for offside as his kneecap was narrowly beyond the line of the last defender.
But the long delay for the decision to be confirmed, in addition to the bizarre irregular lines on the graphic shown by the broadcasters, led to criticism of the VAR technology, which is on trial in the FA Cup.
On Sunday, Hawk-Eye Innovations sought to explain why the grid lines shown on BT Sport’s television coverage did not appear to be straight, with a kink in the line initially indicating Mata was onside.
The system was praised after correctly overturning a decision to rule out Kelechi Iheanacho’s strike for Leicester in their 2-0 FA Cup third-round replay win over Fleetwood in January.
However, it was also described as a “shambles” by former England captain Alan Shearer after the system’s use failed to result in a penalty for Chelsea during their FA Cup replay with Norwich.
Hawk-Eye’s statement read: “A technical error led to an incorrect graphic being provided by Hawk Eye to BT Sport on Saturday.
“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 apologise.”
Hawk-Eye is a computer system used in numerous sports such as cricket, tennis, Gaelic football, badminton, hurling,