How did USC not get hit with a penalty

[gary2]

For the hit on the Utah player celebrating after crossing the goal line?

It was blatant. Might have warranted an ejection?

 

[TheSpecialSauce]

For the hit on the Utah playercelebrating aftercrossing the goal line?

It was blatant. Might have warranted an ejection?

It probably caught the officials off guard. They were used to seeing USC run away from tacking all game.