My son is a homeschooler. Last year he took a first period Tech class at our local HS.
The first few days he would wait outside for me to pick him up. Many adults would approach and ask him what he was doing outside. He would explain that he was was waiting for a ride home.
He asked me why so many people had come out to check on him.
I told him the truth, they were afraid he was an escapee.
What a well thought out responsible thing to say. /SARC
I hope you later told him that they were concerned for his safety and the safety of the other students. That would have been the correct response as well as the mature responsible one as well.