I'm really confused about how this ended. KU had a 4th down with 7 seconds left on their own 16. Their QB ran into the endzone and threw the ball out of the back of the endzone with 1 second left. The refs called a safety. Why wasn't that an incomplete pass and TCU ball on the 16? Does throwing the ball out of the back of the endzone mean something different than throwing to the sidelines?