Oilers head coach Jay Woodcroft issued a coach's challenge on the goal, claiming the Avs were offside on the play. Avs Forward
Valeri Nichushkin clearly didn't tag up by the time the puck crossed the blue line. Shockingly, the NHL review room ruled that because Makar didn't physically touch the puck until Nichushkin had tagged up, the play was on side, despite the fact that Makar had both possession and control of the puck the entire time. The Oilers lost the challenge and had to serve a delay of game penalty.
Nazem Kadri would score on the powerplay for the Avs, and so the NHL's ruling cost the Oilers 2 goals against. The question is, was the ruling correct? The winning margin in the game? 2 goals.