Here's what he said:

“We've done it every Thursday since I've been a head coach, and I think we've done it three times, and two of them have worked out really well, and this was one of them,” Leipold said. “So, it's something that we've worked on. It's something to have just in case. Obviously, we didn't plan on it working the way it played out there, but it was huge. And again, Quentin Skinner, who's on the punt team to begin with, does a great job covering things, was really aware of the situation, landing on the ball.”

 

They try to catch the defense by surprise.  Of course the ball hitting the defender is one of many different things that can happen when its one of your DBs back there and not your regular return man. The receiver is trying to keep the defender from seeing that its a punt and either calling for a fair catch or fielding it and returning it. I am certain that the other time this "worked out really well" the ball did not hit the defender with Kansas recovering.  Otherwise the coach would have said "It worked out exactly as we practice it."