A school is a system, and it can suffer from it’s own systemic issues. I don’t think it’s a good argument to point out systemic issues as a problem yet ignore the fact that schools, private or otherwise, can have the same.
The severity of the injury is fairly irrelevant in respect ro the staff because your argument assumes they are knowledgable enough to know, or willing enough to care to think about it, or even avoiding thinking about the potential severity to psychologically distance themselves from responsibility for the injury or being “the rat” that points it out and gets everyone in trouble.
There are a lot of factors that play into this scenario.
They did not knowingly ignore a severe injury. They did knowingly ignore a possible injury for a kid that (we don’t know the specifics) had a non-normal mental condition that could communicate by screaming a lot over everything. It’s a really big assumption you rely on stating they knew the severity. Some kids with ASD will freak out over transitions, hyper obsess over strong feeling like anger over an injury, big or small. I’ve been around some kids like this and you just don’t know what you’re going to get. Again, these people, on the little info we have, seem to have a problem with this kid. That really sets the stage for them to ignore the kid over some screaming.