Okay I'm not defending the teacher here except for the child's right to be recognized and have their needs tended to. This also isn't about "good" and "bad" teachers, but the education system. This is anecdotal, so take it for what it's worth.

My wife, S, is an intervention specialist which is a teacher in a special ed classroom. I think she is a very good teacher, and after years in a underfunded inner city school, she now works in a very large well funded elementary school in a nice area with very involved and stable parents, by and large.

She has a student, L who is non verbal, most of her kids are and she has the most difficult special-ed classroom in her school. She works on a team with two other intervention specialists, one of which, B, was L's teacher for two years previous. L has a muscular disability.

It's S's first year at this school so she is just starting to know the kids. What she is discovering is that these "very low" non verbal children, have basically received no prior schooling on subjects. Their learning plans have each of them marked very low, with the most basic goals. And granted, behavior is usually an issue with these kids who can't communicate. They can lash out suddenly and scratch or bite a teacher or aide, drawing blood more often than not. So behavior will eat up a ton of bandwidth for any teacher. It took my wife months to get her kids to sit with her and do any work whatsoever. But once they started to do work for her so she could test their ability, she discovers that they are all quite advanced in various areas, despite basically never being taught. Kids with educational goals of being able to count to 5 can do multiplication and division for 2 and 3 digit numbers, ahead of their grade; kids who seem to have no concept of reading or conceptual language can spell and construct sentences or answer questions about a story, if it is shown to them in a way that they will interact with.

Back to L, he is another case just like this. Very difficult to work with at first, refused to be taught, lashes out violently when he gets frustrated, but now that he is used to her he will sit and work and also demonstrates advanced ability in multiple subjects.

However the last to years his previous teacher and the head of their team, B, by all accounts from teacher and aides did nothing with him for 2 years. He was basically laid on a mat in a closet, and ignored, everyday for 2 years. My wife says that for the most part he gets around in her class pretty darn well, so even the assumption that he's mostly immobile was wrong.

Special ed teachers spend most of their time some weeks filling out complicated ed plans that are a state requirement, but frankly no one ever checks or even seems to know how to fill these things out. Everyone is just winging it. Bureaucracy is a stand in for education and the needs of the child. Imo my wife is an exceptional teacher who has time and time again achieved breakthroughs with some of her most difficult students. The lead on her team, with over a decade of experience in this job couldn't even see past their own assumptions about the child, and never stopped to question them, and so the poor kid was neglected, uninjured thank God, for 2 years.

So if a pretty good teacher at a good school can fuck up that badly, how dangerous would it be for a inexperienced or disengaged teacher? To me this isn't a problem that comes down to individual teachers but of the American education system as a whole, and it's priorities. Spoiler alert, politics matter more than children.