It was one of the most talked about plays from Thursday’s Eastern Conference Knockout Round match between Atlanta United and Columbus Crew SC.

In the 40th minute Crew SC’s Justin Meram threaded an attacking through ball to teammate Pedro Santos. Assistant referee Andrew Bigelow raised his flag, indicating an offside position by Santos.

Despite the flag, Santos continued his run and fed teammate Ola Kamara, who redirected the ball into the back of the net. But referee Allen Chapman had whistled the play dead just as the ball was heading in Kamara's direction.

With replays showing that Pedro Santos may not have been offside, many wondered why Video Review wasn’t employed to review the offside call.

Per the Video Review protocol established by The International Football Board (IFAB), Video Review can only be used in cases of clear and obvious errors in four specific instances of play: (1) goals, (2) penalty kicks, (3) direct red cards and (4) cases of mistaken identity.

Given the whistle by the referee Chapman came before the ball was put into the back of the net, a goal was technically never scored, ruling out the possibility of Video Review by the head referee.

After a 0-0 draw following extra time, Columbus Crew SC would go on to win the match in a penalty-kick shootout, advancing to the Eastern Conference Semifinals against New York City FC.