By running into the kicker, R fouled behind the LOS taking PSK out of the equation. So K has the ability, with the acceptance of the penalty to replay the down. That 5 yard walk-off would move the ball to K's 10 - making it 4th and 10 from the K 10. Then, R's DBPF would be enforced from the succeeding spot - K's 10 - giving K a first down at the K 25.