It was rainy and windy and ND had a ton of injuries. They got up by 2 TDs in the first quarter and shut down the offense for large chunks of the game. They were being deliberately conservative. I'm not sure why people are confused about this. There were tons of turnovers. Louisville had more yards and better ToP because ND was playing conservatively on both sides and protecting a lead.
It ALMOST backfired but it didn't and they got out with a needed win. No one should be complaining.