Earlier quoted context omitted.
You totally nailed it. 100% right. Distilled it down to the essentials of how the internet works and the nature of a protocol as a contract. Bravo.
His whole analogy only works because the librarian is a human, and if a human with some apparent authority lets you do something, you can reasonably infer that you have permission to do it. But you can't anthropomorphize a server like that. It's not a gatekeeper, capable of granting permission, just a dumb lock which may be flawed. Only humans can consent. To repurpose his analogy, if you sneak into the staff room an…
There are any number of explicit steps that are taken to put code on an HTTP service on the internet.