[jehlakj]

Maybe I'm not understanding this, but wouldn't network issues take priority naturally? For example, if there's a problem with a database connection, you'd return 500. How would you know if the resource even exists?

[treis]

Network issues between the client and the server.

[NoGravitas]

Those will never return a 404, though.

[treis]

If your DNS server has the wrong IP for a URL it will.