Yes and no. IMO, the hit into the boards is what got the penalty. However, Kozek has to realize when the puck is gone and when to hold up. If he would have lightened up, he most likely would have still bumped him and knocked him over, but I doubt he would have hit the boards with the same impact, and no penalty would have been called.
Again, it goes back to me trying to see a a game both ways, rather than just as a Sioux fan.