You'd really have to determine if there was any participation by any of the nonplayers, and I don't know how you'd do that without watching the film. The camera view shown has mostly Black players coming on early, and they obviously didn't help their team's cause.
Assuming that there was no participation, all penalties will be from the succeeding spot. Black came on first, so the ball goes to the 1.5. Now penalize White to the 16.5. If any official saw White hanging from the goalpost (unlikely), that USC puts the ball at the 31.5 for the try.
I probably wouldn't have an USC on the White coach, but I would shoo him back toward his sidelinewhile the conference is taking place.