Say it better?
 

HS Varsity game. Lefty batter tries bunting (not slapping but it shouldn't matter).

She bunts and the ball goes into the air only a couple of feet above the batter's head. She starts going to first but cannot avoid running into the ball as it's coming down and the ball hits her in the left shoulder/upper chest area.

I have a dead ball and the batter out for coming into contact with a fair batted ball.

Coach questions the call and claims the batter shouldn't be out because she was still in the batter's box.

My reply: "Coach, part of the batter's box is actually in fair territory, and the batter contacted a batted ball while it was over fair territory."

She asked me to check with my partner, who was in C at the time. So I did, he couldn't offer anything new, so we stayed with the call.

Could I have explained it better?

"In my judgment, the batter runner was in fair territory."

If still in the box, it does not matter if the fair part or the foul part.
That only matters to the ball, not the batter.

Now, with a lefty batter, out of the box that quickly is reasonable, but surprising.

Okay, two rules come into play here:

And then there's:

So which was it? Did the batted ball come down and touch the batter, or did the batter run into the batted ball? There's a difference, and in one, the batter's box is relevant, while in the other it's not. You said the ball hits her, which makes it sound like this met the criterion under the Foul Ball definition.

But if it really was a case of "player contacts ball" versus "ball contacts player", then you should have just told the coach, "Coach, the batter's box is irrelevant when it comes to the batter making contact with her batted ball. She's either out if she touches the ball was in fair territory, or it's a foul ball if she touches it in foul territory." I judged that the ball was in fair territory.

I hope this pertains strictly to FED ball, because NCAA states flat out that if she contacts a fair batted ball with a foot still in the box, it's a foul ball.

Ok, now I'm a little confused. Most batters are up in front of the plate while in the box. (that puts their front foot in fair territory). So, if a batted ball goes straight down and hits her ankle on her front foot, she would be out????

Actually, both.

No, a batted ball which hits the batter while in the batter box is a foul.
Even if the batter is in the fair part of the box, rules designate that a foul.

Can't have both, because each calls for two completely different and conflicting calls. You either have "ball contacts batter" which is a Foul Ball if she's still in the box, or "batter contacts ball" which is an Out if the ball was in fair territory.

What you say better to the coach--which is the subject of your original post--needs to be a clear articulation of what happened. It's gotta be one or the other.

A batter unintentionally contacted a batted ball. DEAD BALL. FULL STOP. Every time.

-- Item A: Where is the batter; specifically, where are her feet? If in the box, foul ball. If a foot is on the ground wholly outside the box at the time of contact, she's no longer in the box. Go to Item B.
-- Item B: What is the ball status? If foul, foul ball. If fair, dead ball + out.

Danger, Will Robinson.

Wasn't the ball in flight? Ball location becomes irrelevant if the catcher, or any other defender had the opportunity to make a catch.

True. The instance of a batter being out of the box and interfering with a foul fly ball, or intentionally interfering with a ball anywhere on the field, is so rare I left it out for brevity.