[JRutledge]

You have an Inadvertent Whistle, which means the offended team (the team with the ball) has the option of taking the place where the ball was ruled dead or they can replay the down. Anytime you have a penalty, the penalty must be administered if accepted. It sounds like the team with the ball choose the option to replay the down and since the USC penalty was administered as well; the ball would be placed after the penalty half the distance to the goal and repeat the down. It sounds like they got it right considering they had an IW.

Peace