That could well be the case. In my state, NY, we are actually forbidden from doing that. We MUST inform the guidance counselor, principal or assistant principal and only THEY are authorized to call LE or Child Protection. We would get in trouble for usurping their roles and making a judgment call we are not considered qualified to make.
However, I'm trying to picture how that would work if in my state, teachers were obligated to make the call themselves. I certainly couldn't halt class and make that call in front of other students. I couldn't make that call in front of the perpetrator, either, because who knows what the reaction would be if that put him over the edge while in class? Then I also can't see waiting until I had a free period, while letting it slide by in the meantime. IMO it has to be handled immediately and that's why admin or a counselor, who also have training in crisis intervention, are supposed to do that.
ETA: at least in my school, we weren't even allowed to call 911 if there were some kind of medical emergency. We had to call administration and they'd have to call.
THAT is something I've never understood. We are acting in loco parentis, seconds count, but those were the rules. I'm recently retired but I don't think it's changed.
