Haven't seen the video. But would bet money that the coach also stresses the importance of:
- checking your grip to line up your knuckles;
- that the "load" is a static position that usually results in the girls shifting their weight back towards the catcher and "freezing" there (see RichK's post above);
- palm up / palm down at contact (which I've even heard Antonelli talk about, but it's always been a non-teach for me, even with beginners?); and
- ending with the final "positions" of extension, then follow through.