Juan Mata thought he had put United 2-0 up against Huddersfield Town just before half-time in their FA Cup fifth-round tie on Saturday following Romelu Lukaku's early opener.
However, after a lengthy delay, referee Kevin Friend disallowed the goal for offside on the recommendation of the video official, located in a studio in London nearly 200 miles away.
Yet the lines used to determine whether Mata had been standing in an offside position showed up on television footage as anything but straight, leading many viewers to think a decision had been using inexact information.
However, Hawk-Eye -- the company behind the system -- insisted they had given the correct information to the VAR if not broadcaster BT Sport during a match United eventually won 2-0 thanks to Lukaku's second goal.
"A technical issue led to an incorrect graphic being provided by Hawk-Eye to BT Sport last night," said a company statement issued Sunday.
"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."
United manager Jose Mourinho, speaking after Saturday's match, said: "I think our game is so beautiful that to change we have to change for the better.
"If they find a way in the VAR that the VAR is always right and always bring the truth, I'm happy."