I firmly believe that there are multiple viewpoints on almost everything in this game: linear or rotational? Alligator-style fielding or hands side by side when fielding a ground ball. Step & drag vs leap (careful using this term) style pitching.
However....nowhere in this game should ANY batter be rolling their hands at or before contact.
I certainly don't consider myself as knowledgeable about the swing as maybe Tim Duncan or Howard (plugs for you guys), but I think I know enough about the mechanics of the swing to know that this person is flat out wrong.
Now...what to tell your DD? Therein lies the long-standing problem of an athlete playing for more than one coach at a time. In fact, this isn't even a problem of playing for more than one coach in a season...this problem could exist if she ONLY played for this team & she was being led by a coach with these beliefs.
So, how do you approach the coach? You certainly can't go directly to the coach & say "You're wrong", because DD will suffer. What do you do? Maybe find a way to get copies of some articles or something to describe effective hitting motions & see if you can gently get them into the coach's hands. It's a delicate process.
If one of my players' parents brought me a book showing a fielding technique that was different that what I teach, would I be offended? Sure...I would feel as though I don't have their confidence.
I am really looking forward to the input from some of the guys and gals who have more experience with this. How did they deal with it? Was it successful?
Bottom line....Larry......palm up/palm down at contact. All of the hitting gurus believe in this.
So do I...so do you.
So should this coach.
Good luck!