Arizona's second 7 points came on an interception.
Arizona's third 7 points came on a kick return.
Iowa actually does have one of the best defenses in the country. Their defensive coordinator wasn't at the game because he was in the hospital. Also, Iowa did erase a 27-7 lead despite giving up 21 points while Arizona only had 13 yards of offense.
I hate to defend Iowa but our Vols probably would have folded and lost by 50+.