Kickoff play

[sm_bbcoach]

Need a confirmation about a ruling please:

K.O. from K's 40. R26 muffs the reception at his own 7. I (as referee) wind the clock and continue to officiate. Ball bounds into R's end zone. I rush in with a heavy selling job of touch back. It was the force of the KICK that put the ball over the goal line. The muff can not give it new force.. Coach of K disagrees with me. HE claims that I did not give his kids the chance to pounce on the ball for a TD since R touched it and made it live. I tried to explain the force thing on a muff and that his kids are only pouncing on a dead ball.

Am I right? I am really confident about the call.