It comes down to the general accidental touching of a kick by R, which "counts".
If R48 isn't paying attention to where the ball is and the falling punt glances off his shoulder, K can recover.
If R48 is looking to block a K player, but hasn't found one and stumbles backwards into the ball because he doesn't see it behind him, K can recover.
Intent to touch the ball is not required, R is responsible for knowing where the ball is unless actively engaged in a block.