[usc2626]

In the 2012 NFHS case book 6.2.5 situation C;

With fourth and 5 from K's 30 yard line , K9 punts the ball downfield where it's grounded and touched by K88 (first touching) at R's 30. The ball continues rolling and is picked up by R35 at R's 25 yard line. R35 is subsequently hit and fumbles at R's 28. The loose ball is recovered by K88 on the ground at R's 26. During the kick, R55 is flagged for holding. Ruling: If K accepts R's foul for holding, then it is enforced from the previous spot with a re-kick since post-scrimage kick cannot apply as K is next to put ball in play as a result of the play. If K accepts the foul, the awarded spot for illegal touching is not applied. If K declines R's foul, R will take the ball at the spot of first touching. (2-12-1; 2; 2-16-2h)

My question is if K accepts the holding why is it a re-kick after enforcment from previous spot and not a first down for K after marking off the foul since it was fourth and 5?