Even in my day, certain teachers were hounded. And at least 75% of those you would NOT have dared do it with never used CP nor would they have called the Head to sort it out.
I suspect Doc himself would have garnered that respect at any time & in any school system with or without CP. And part of that respect is from your fellow teachers. Which also makes me wonder whether Mr Harvey’s colleagues were disdainful of him & this spread to the kids.
In any ongoing occupation, teaching or other, there is and needs to be a range of experience and ability. Most practitioners are in the middle. A few are outstanding and some struggle. Ideally, the very best people are attracted, nurtured, developed and retained in important occupations like teaching.