Deadball on Kickoff

[trainman52]

K kicks ball 6 yards and ball rolls to a stop. Niether K or R make any attempt to down the ball. At what point should it be called dead? If both teams are standing over it and R goes to touch the ball to down it and at the time of touching K grabs the ball and falls on it, whos ball is it. The ball was idle for at least 3-5 seconds before the touching.

Thanks,