Realized later that it was probably someone who was not prepared for their exam who asked someone to call in or he/she did it themselves.
Doing something like that takes guts! You can get caught out for such an act of lunacy! I guess desperate times, calls for desperate measures.
No matter how bad your problem might be, life is something that shouldn't be taken for granted, because the next time there might be a real bomb scare, and then no one reacts.