If I was Jay Hill, I wouldn't have coached them to do it any differently. And those who say they would have don't understand that the bigger risk on that 4th down was the "receiver" getting open when his DB looks back and watches the QB to make sure he punts it. What happened to us was one of the flukiest special teams things I've ever seen.
Second one, on-side kicks are successful about 20% of the time, even when the other team expects it coming. I didn't see anything egregious from a coaching perspective, our guy hadn't started running back and had to come back for the ball. He just didn't field it cleanly.