Thorne is more like apples and oranges to Ott than apples to bowling balls. Thorne played in only 8 games - well under the 30% requirement. He did attempt a comeback by playing in a game after the second half of the season started, which would appear to disqualify him under the rules. But, that's where the similarity in the two end. Thorne attempted to come back, and played 19 minutes in one game. Apparently, he then had medical complications, which as I understand he was able to show was directly related to the original injury and apparently (according to his medical records) exacerbated by his diabetes. So, he did attempt to come back and did play - but suffered a set back to the same injury as a result, which then forced him to be shut down for the year. The original injury did in fact turnout to be season ending- despite the comeback attempt. He was still under 30% of the games. The appeal had nothing to do with how much playing time he had in any of the games he played in. The hardship ruling excused the fact that he appeared in the one game in the second half of the season and was based on his unique medical situation (I wouldn't be surprised if there were ADA claims brought up in that case due to his diabetes.)
On the other hand, Ott's initial injury was an elbow injury. Had they shut it down then or if he had tried to come back in a game and found he couldn't continue, while staying under 30%, he probably could have qualified for the hardship, but he continued to play, indicating that the injury was not season-ending. It was his and his coaching staff's decision to keep playing. of course, they could not have anticipated he would tear his ACL. That occurred in his 6th game, after already having played over 30% the games. Unlike Thorne, Ott didn't attempt to come back from the elbow and experienced complications that rendered him was unable to perform the rest of the season. In fact he was able to come back - and apparently was relatively healed by the Illinois game, before suffering a completely unrelated injury. Also, Ott had no underlying medical condition.
Simply put, the Thorne situation is not on all fours with Ott's circumstances. If Iowa's staff truly thought the Thorne case was good precedence for Ott's case, Iowa's athletic department needs to go next door and find a couple of law students who could have provided better analysis.