The decision left Mikel Arteta "fuming", pundits were baffled, while Arsenal fans were furious.
The Gunners may have beaten struggling Wolves 1-0 to maintain their Premier League title hopes - but it was Myles Lewis-Skelly's controversial red card that stole the headlines.
In the 43rd minute Lewis-Skelly caught Wolves' Matt Doherty above the ankle to break up a counter-attack on the edge of Wolves' box - about 70 yards away from Arsenal's goal.
Referee Michael Oliver showed the 18-year-old a straight red card, a decision which was upheld by the video assistant referee (VAR).