Ooooohohohohoho you would SO get expelled for that, since it's a much more violent reaction than what happened here. K-12 schools are largely totally unreasonable organizations run by completely unreasonable individuals who wouldn't make it in the real world.
Let's assume just for the sake of argument that every actor from their own perspective is reasonable.
The problem is that a small group of parents are at the top of the "food chain." These parents are self-selected and therefore have a more overbearing personality (i.e. helicopter parents) than average.
So these parents sit in PTA meetings or similar and pass more and more rules based on the latest moral panic (e.g. guns, knives, hairstyles, video games, healthy food, etc). They aren't trying to strike a "balance" to find what is reasonable they're trying to keep the kids safe even at the cost of everything and everyone else.
Now you might say "but isn't the principal in charge?!" well, no, not really. I mean the principal is in charge of certain things but if they fail to keep the PTA happy they will be replaced by someone who will. Child safety (as the PTA will spin it) is one of those areas where principals have very little freedom.
With this specific incident in mind, even if the principal AND the teachers thought it was crazy to both exclude and arrest her, they might have effectively zero say in the matter.
Exactly. A lot of people have no idea how it really works -- the "noisy" members of the community have a lot of control over how things are run since they can have someone fired/impeached for not kowtowing to every crazy knee-jerk demand.
