Referee Robert Jones and his VAR team may have made a big mistake in the recent Manchester United win as they didn't send off Aleksandar Mitrovic for a headbutt.
Having already secured Champions League football, the Red Devils were looking to finish third in the Premier League as they took on Fulham.
Marco Silva's men were destined to end the season in a very responsible tenth, easily smashing their pre-season aim of avoiding relegation.
Despite having nothing beyond pride to play for, though, the away team still played well and took the lead in the 19th minute as Kenny Tete headed in Willian's corner at the near post.
However, Man United hit back before halftime as Jadon Sancho finished from close range. A second-half strike from Bruno Fernandes was then enough to seal a 2-1 win at Old Trafford.
In the 79th minute, with Fulham now chasing the game, they came forward with an attack which saw Mitrovic grappling with Tyrell Malacia to get on the end of a cross.
The opportunity came to nothing as the ball bounced out of a play but that didn't mean the two players were happy to let go of one another.
Indeed, with the pair on the ground, as Mitrovic tried to get back to his feet, he appeared to flick his head forcefully in the direction of Malacia - as seen in the Match of the Day highlights (1:21:49).
The Fulham striker was ultimately booked on what was a difficult afternoon as he also had a penalty saved by David de Gea. However, it's safe to say he was lucky to avoid a red card for this headbutt on the Man United left-back.
Seeing as though Mitrovic has only just returned from an eight-match ban after pushing referee Chris Kavanagh - incidentally in another defeat at Old Trafford - he would perhaps be wise to learn how to control his anger a little better.
On this occasion, it really does feel as though he got away with one, but evidently, the VAR assistant didn't believe it was quite bad enough for them to get involved and overrule the initial decision by referee Jones.
The Athletic's Laurie Whitwell took to Twitter to comment on the situation, noting how it had been "another bad day at Old Trafford" for the striker as he was subbed immediately after "shoving his head at Malacia".