I agree that it wasn't even close to being checking from behind. I've quoted the charging rule below from the 2006-08 NCAA ice hockey rulebook. Note that while it says that a player "shall not skate more than two steps," it also says charging relates to "distance traveled."
As I watch the video, Kaip took maybe two steps. It looks more like one and a half to me. So I don't think the steps he took should factor into it, but the distance he traveled before making the hit might.