This isn't really true. ISU had a great gameplan that day.One play, nope AJ ran past him continuously.
1) Attack Iowa's #5 CB
2) Moving pocket away from AJ
3) Cut blocks by the tackle with RB help
4) Fast rhythmic passes
They were decently successful with this strategy, but Iowa adjusted fairly well and the score showed that. One of the memorable times they went away from this is when they were taking shots in Iowa's endzone and the left AJ one on one, he got good pressure and Purdy had to sail it over the WR that OJ was covering in the endzone. Their tackle did play him really well in the run game IMO.
You can still watch the game if you want. The first half has a ton of examples of the moving pocket and quick throws away from him.