She didn’t get “clearance” at the office to proceed past the office. The “buzzing in process” ONLY gets you to the office and NOT to the rest of the school. That’s the process that’s in effect for most schools. I’ve been through it many times - even when I’ve been called to come down, by the school.
Okay Barney Fife. If you don't want parents, whom you know, to show up at school in a state of worry, don't call them and tell them there's something wrong with their kid and to come down and then expect them to not act like a worried mother.
Mama Bear/Cub. Don't get in the way Barney or you'll lose your ass - in this case via lawsuit.