Mbappe was clearly in an offside position when Theo Hernandez tried a through-ball, but Spain defender Eric Garcia played the Paris Saint-Germain striker onside by touching the ball when attempting to intercept the pass. France won the final 2-1 (stream the replay on ESPN+ in the U.S.)
Referee Anthony Taylor allowed the goal because Garcia had made a deliberate attempt to play the ball, a decision backed up by the VAR.
Refs' chief Roberto Rosetti has confirmed the decision to allow the goal was correct, but feels it is not in the spirit of the game to allow an attacking player to profit from being in an offside position.
"Anthony Taylor made a correct decision based on the existing law and its official interpretation" Rosetti said, in quotes reported by the Press Association. "The player [Garcia] deliberately intervened to play the ball and the opponent [Mbappe] was not interfering with play.
"However, this case shows us that the current interpretation of the law appears to be in conflict with the spirit of the law itself, which is to prevent any player from taking advantage from their offside position.
"UEFA's stance is that there are ways to improve the wording to bring it into line with the aim of the offside law and of the spirit of the game."
Rosetti is on the Technical Advisory Panel of the International Football Association Board (IFAB), which proposes modifications to the Laws of the Game. The panel will meet on Oct. 27, before the Annual Business Meeting of the IFAB on Nov. 25 will finalise any changes to go to a final vote early next year.