Mikel Arteta was quick to voice his anger on Saturday as he felt Ivan Toney's eqauliser against Arsenal should have been ruled out for offside.
The controversial goal eventually cost Arsenal a point, as the game finished 1-1 after Leandro Trossard's earlier goal.
Sportsmail's Chris Foy, an ex-Premier League referee and PGMOL representative, explains how the decision was made, and what should have happened.
Ivan Toney puts the ball in the net and VAR Lee Mason obviously runs through the checks.
VAR was looking to see if there was an offside and whether Ethan Pinnock had blocked off Gabriel in the build-up.