These are just two signs of a bad instructor....
1) Lessons are VERY inexpensive. Groups are big and horses do not stop. This is unsafe. I watched a group lesson with 4 students in it, horses were not suitable for them and they all ran in circles for most of the lesson.
2) Instructor claims to specialize in X but her students do not ever place in X, nor does she teach her students to move the horse correctly to perform X. (X is my discipline as well, and this ain't right). Do your homework and make sure you're getting correct instruction. READ and make sure your instruction is aligned with your discipline's standards. This particular trainer does give the impression of confidence.
So, just a tip. Be educated and be safe.