Though unintentionally, they really hammered it in that he's not one of them, even if he's working there regularly.
That being said, it would be better if he was aware of the disaster drill content. Without being aware of that, it might have a bad result since a random customer would obviously assume he knows that stuff, even though he doesn't. He would, in fact, be in the same position as the library visitors. Maybe there's a legal reason why he isn't taught that, though, so that he can't be held liable for anything that might go wrong; he's not a real, properly educated employee, after all. But, again, if there's a bad earthquake or fire, for example, and a customer sees an obviously employee looking person and seeks help from him, is it better or worse that he can't help due to judicial reasons? It might cost lives that he knows nothing.