Los Angeles hung on for the victory when a 3-point attempt by Minnesota's Ricky Rubio to send the game into overtime was blocked from behind by Bryant.
"Video review by the league office confirmed that Kobe Bryant fouled Rubio while Rubio was in his shooting motion," the league said. "Rubio should have been awarded three free throws."
The shot in question came with 3.4 seconds remaining in regulation.
Despite the statement, the final score will stand.
The Los Angeles win allowed the Lakers to maintain a one-game lead over Utah for the eighth and final playoff position in the Western Conference.