The Hoops supporter was thrown out of the stadium and given an immediate life ban after running on to the pitch and attempting to assault the French attacker during the game against Paris Saint-Germain.
He was condemned by the rest of the Celtic support at the time and has continued to face a backlash afterwards.
But despite the criticism, it was only accounts of fans at the game and pictures that painted a picture of what happened – until this video of the incident appeared.
It was posted to Twitter by French journalist Paul Rouget and doesn’t reflect well on the fan:
— Paul Rouget (@PLRGT) September 14, 2017
Just what was he thinking?
UEFA could decide to punish Celtic for the incident, risking some big repercussions after other incidents involving supporters in European games over the last year.