You have a fundamental lack of understanding of child development. This is why we were abused as kids.
For so many goddamned reasons— especially if you don’t know anything about the kids— the word “behave” in this usage should not be allowed in adult usage. All it does is perpetuate harmful and false beliefs about children.
At the same time, there is clearly a need to show that actions have consequences and that if you break rules you’re punished for it. If the driver pulled into an abandoned parking lot and made them deboard in nice weather and stand there for 15 minutes before resuming, that would be fair. As adults it’s on us to guide children, and that means reinforcing good actions and discouraging bad actions – escalating to punishment if they keep acting out.
I agree with you that the person you’re responding to is being absurd. Punishment has to be carefully done. You need to create a situation that is undesirable but has absolutely no danger to their health nor wellbeing. Is that difficult? Yes. But that’s why we’re the adults.
The school should have worked with the driver much earlier to address the situation, before it escalated to this point. Even adults can only take so much, but it’s still on us to not lose control.