Late in the game on Saturday evening at the Aviva, with all still to play for, Cian Healy was yellow carded.
The Leinster prop, who had just come off the bench to replace Jack McGrath, put in a no-arms tackle on fellow loosehead Dave Kilcoyne.
After viewing a replay, referee Ian Davies dished out a yellow card. Healy would play no further part as Leinster held out for a three-point win. That was despite Munster being just metres from the try line with minutes remaining.
On Instagram today Kilcoyne posted some video of the tackle and stated that Healy should be locked up - not for its illegality but because the Munster man still managed to cross the gainline.
Unwilling to accept Kilcoyne's victory, Healy pointed out that to cross the gainline, you are required to have possession of the ball.