José Mourinho has suggested that referees should ultimately be the ones to decide whether to continue testing VAR following more controversy on Saturday evening.
However, Juan Mata latched onto a precise Ashley Young pass before rounding Jonas Lössl and slotting home to double the visitors' lead just before the break, only to see his goal disallowed by the VAR system.
Mourinho claims to be best behaved boss
Frustrations were partly due to the space of time referee Kevin Friend took to discuss with Neil Swarbrick in his earpiece, but the image used to prove Mata was in an offside position presented an uneven line.
Mourinho explained that he understands VAR is still at an experimental stage but hinted that his view on it could've been different if the incident affected the final result.
"Yeah. The words of the protocol are something like a clear and obvious situation, and for sure it wasn't a clear and obvious situation. But we know that it's experimental and we have to accept it, but I'm speaking after a 2-0 victory."
The United boss has a troubled past with referees and the media, but joked that he was on course to be named the "best behaved manager" in the top-flight this term in relation to not overreacting about VAR.
"As you know, I'm close to winning the best behaved manager in the Premier League this season, nothing can make me lose that trophy. The feeling is a bit strange and I was sharing the feeling with David [Wagner] and Anthony Taylor on the touchline which was doubt."
Referees should get final vote of confidence
Following the incident, Mourinho was keen to move on and not let his team dwell on it, saying: At half-time I had to tell my analysts and assistants to shut up 20 times because I don't want the players to know what happened.
"I want the players to feel like it was an offside so they can move on without without sad and unhappy. But, one day it will go in our favour."
Asked if VAR should be given a chance, the Portuguese manager shared his view that the people who use it, the referees, should decide despite the frustration it's causing fans.
"I was saying to Taylor and [Kevin] Friend after the game that I think it should be the referees who decide. Do they want it? Do they feel happy with it? Do they want to have technological help? Do they want to leave the human mistakes that they sometimes make?
"But I think if they stick with the words of the protocol everyone will be happy."