Something similar happened up here, actually in one of the eastern Montana ranching/farming communities. A girl had been out early hunting antelope with her father and went to school with her rifle in the trunk of her car. A teacher overheard her telling her friend that she had the rifle and wanted to call the sheriff. But the principal stopped that, got the girl's rifle and held it in his office until end of school, when he returned it to her.
No follow up on whether she filled her antelope tag, however.