Ahead of Sunday's NBA All-Star Game, Mitchell dismissed James' comments made at the Jazz's expense when he left two Utah players until the end of the All-Star Game draft.
The tournament will tip off on Wednesday at T-Mobile Arena in Las Vegas.
In a shrunken field of just three dunkers, Simons beat Toppin and Stanley to become the first Trail Blazer to win the dunk contest.
Golden State's superstar stole the show in the All-Star Game first half in Atlanta.
Curry splashed his final three of the evening as he held on to beat Mike Conley in the final round.