UEFA has provided written explanations as to why various decisions were made with or without the aid of VAR in the Champions League last-16 matches that affected Real Madrid, Paris Saint-Germain and Roma.
In Tuesday's game between Ajax and Madrid, that saw the Dutch side claim a remarkable 4-1 win, VAR was unable to definitively conclude that the ball had gone out of play by the touchline during a move that would see Dusan Tadic score the visitors' third goal.
PSG fans, meanwhile, were left aggrieved when referee Damir Skomina awarded United a penalty in the dying moments of the game after VAR ruled that the ball had struck Presnel Kimpembe's arm as he attempted to block a Diogo Dalot shot.
And there was also controversy in Roma's exit at the hands of Porto, that saw the Portuguese side awarded a penalty after Alessandro Florenzi was adjudged to have pulled back Fernando, while VAR did not intervene when the Serie A side felt they should have been awarded a spot-kick for a foul on Patrik Schick.
Here are the full written reasons provided by UEFA, including the imagery to support the explanations...
Real Madrid 1-4 Ajax
Ball in/out of play - 62’
There was no conclusive evidence that the ball would have been entirely out of play from all video angles and images that were carefully analysed by the VAR.
The assistant referee, who was perfectly positioned, had adjudged that the whole ball had not fully crossed the touchline. No on-field review was therefore required. Consequently, the referee was right not to intervene and to allow the goal.
PSG 1-3 Man Utd
Penalty award - 90'
The VAR, after checking various different angles available to him, recommended to the referee an on-field review following the penalty area incident.
Given that the referee did not recognise the incident clearly during live play (referred to as serious missed incident in the VAR protocol) an on-field review was conducted.
Following the on-field review, the referee confirmed that the distance that the ball travelled was not short and the impact could therefore not be unexpected. The defender’s arm was not close to the body, which made the defender’s body bigger thus resulting in the ball being stopped from travelling in the direction of the goal. The referee, therefore, awarded a penalty kick.
Porto 3-1 Roma
Penalty award - 116’
The VAR, after checking the offside line - which confirmed the attacker to be onside - asked the referee if he had seen the holding offence committed by the AS Roma defender.
The referee confirmed he was unaware of any holding during live play and he asked for the images to be prepared to allow him to conduct an on-field review (serious missed incident). The review convinced the referee that a penalty kick should be awarded for a holding offence.
No VAR intervention - 121’
The referee was close to the action and had himself seen the potential incident in live play and judged that there was no foul.
The referee nevertheless decided to delay the restart of play, to give more time to the VAR to review the different camera angles available. A VAR check was conducted, and the various images were studied carefully by the VAR, who did not find any clear evidence.
The referee was then informed by the VAR that following the check no clear and obvious error had occurred and that there was no ground for a VAR intervention and an on-field review.
All the above-mentioned decisions were made in full compliance with the VAR protocol.