Batter kicks dropped pitch

[Ran.D]

ASA rules. Runner on 3B. Pitch bounces off catchers glove and rolls a few feet up the 3B line, runner is coming home.

The batter is backing out of the box and is totally out of the box (not sure if this matters) when she kicks the ball towards the dugout allowing the runner to take home unchallenged.

I'm coaching and argue (politely that it should be interference, PU says it has to be intentional. I inquire, what's different between this and a batter stepping out of the box and interfering with the catchers throw? PU says "that's totally different"

My rule book is a little dated but says "defensive players must be given the opportunity to field the ball anywhere on the playing field without being hindered"