The impression I'm getting about the teacher was that she was trying to get that training/certification by "learning" on OP's son without doing the legwork to actually learn about OP's child.
It's like saying "Oh I will get a certification in working with the rectangles to add to my other qualifications in working with circles, triangles and squares!" But for a year, instead of trying to learn how to work with rectangles, she repeatedly just tries to shove that rectangular shape into a square shaped hole because well hey, they're so similar that it will work! It's just the rectangle and his mother that are just being so darned difficult and she just can't understand why she can't get the rectangle to go into the square hole and she just KNOWS it will work if it weren't for the rectangle's difficult mother!
Meanwhile his mother is going to the administration saying "Please help my son, this woman is trying to use the techniques for squares on my son and he's not a square so he's not going to fit into that hole and I'm worried she's going to damage him somehow by trying to make him fit! Please help her understand she has to learn methods for rectangles and make her stop using the square methods on him because he is NOT a square!"
I don't fault the teacher for wanting to get more experience and learn how to help children, but this one seems to have been rather lazy in doing so. Instead of actually learning techniques to work with the purple disability, she kept trying to force the ones for pink disability on him, willing them to work and refusing to understand why they didn't. Thus trying to shove a square peg in a round hole, or like my analogy,a rectangle in a square hole.
I'd have a lot more sympathy for the teacher if she'd read a book, attended a seminar/class or two and actually tried methods for the purple disability. That would show she was actually trying to help OP's son, not just trying to get away with saying she was helping him when she really, really wasn't.