Interference by batter/runner?

Question
Batter takes a big swing and drills the ball straight down into the batter's box where it comes to a stop clearly in fair territory, but still inside the batter's box. Batter starts to run and inadvertently kicks the ball while he and the ball are the batter's box. Is this interference on the batter/runner or is it a foul ball because it was contacted while still in the batter's box? Please answer according to NFHS rules.

Answer
Mark,

As long as the contact is not intentional, it's a foul ball:

8.4.1 SITUATION B: B1 squares to bunt and hits the pitch. The batted ball
bounces off the plate and hits B1抯 (a) leg or, (b) bat a second time while B1 is
holding the bat in the batter抯 box (no foot is entirely outside of the batter抯 box).
RULING: In (a), it is a foul ball. In (b), the ball is foul unless, in the umpire抯 judgment,
the ball was contacted intentionally, in which case the ball would be dead
and B1 declared out.