Yes, coaches do this, but it isn't reviewable during the game. It was a bang bang play with fast moving parts. I look at it and say he leapt through a gap and got clipped on the way through, you look at and say he leapt over the player. This isn't black and white and I feel it was a good no call on this particular play and the refs on the field got it right.
The gap rule applies more so at the line of scrimmage not where the infraction actually occurred. The MN player had established a defending position and the Iowa player tried to go over the top. Jesus this isn't that hard.