I was at the game and mid-way through the third quarter there was a USC injury so there was a commercial timeout. The USC injured player left the field after about 30 seconds. The break continued for what seemed like another 10 minutes or so. The energy in the stadium completely drained during that ridiculously long commercial break.
I think NBC and their crazy long commercial breaks could be a major factor in the lack of ND home field advantage. I know there's a 15 game home winning streak currently but before that break the crowd was into the game and LOUD. After the break it was pretty quiet and USC started the comeback thusly.
It was a turning point in the game.