Here it is. As you can see on the replay, Phillip Buchanon made a horse collar tackle on Adrian Peterson. The personal foul was not called by the officials. We will see if the NFL fines Buchanon for this.
If a penalty had been called, it might resulted in the Lions still getting the ball, with the penalty being assessed after the touchback. It looks like Buchanon knocked the ball out before making the horse-collar tackle.