(a) R23 has caused the ball to go OOB. R's ball at the R19.
(b) K's kick has gone OOB. R may take the ball 25 yards from where it was kicked, have K re-kick, or take to ball at the 19.
I know this would be the ruling if the ball was caught in flight. I see no reason for a grounded kick to be any different. But I've been wrong before.
