Hawk-Eye has "unreservedly" apologised to Sheffield United after they were robbed of victory at Aston Villa by goal-line technology on Wednesday.
United should have been in front late in the first half when Villa goalkeeper Orjan Nyland carried the ball over his the line after colliding with team-mate Keinan Davis.
Yet no signal was sent to referee Michael Oliver's watch, so what would have been the only goal of the first game since the Premier League was shutdown due to the coronavirus pandemic was not awarded.
Hawk-Eye, the operators of the technology, confirmed after the game that the goal should have been awarded, but cameras were "significantly occluded" by Nyland, a defender and post at Villa Park.
"During the first half of Aston Villa v Sheffield United match at Villa Park, there was a goal-line incident where the ball was carried over the line by Aston Villa goalkeeper, No. 25 Nyland," a Hawk-Eye statement read.
"The match officials did not receive a signal to the watch nor earpiece as per the Goal Decision system (GDS) protocol. The seven cameras located in the stands around the goal area were significantly occluded by the goalkeeper, defender and goalpost.
"This level of occlusion has never been seen before in over 9,000 matches that the Hawk-Eye Goal-Line Technology system has been in operation.
"The system was tested and proved functional prior to the start of the match in accordance with the IFAB Laws of The Game and confirmed as working by the match officials.
"The system has remained functional throughout. Hawk-Eye unreservedly apologises to the Premier League, Sheffield United, and everyone affected by the incident."
The Blades would have moved above Manchester United into fifth place with a victory, while second-bottom Villa are now just a point behind Bournemouth, Watford and West Ham.
