ISO 9660 puts its primary volume descriptor at logical sector 16, which is byte offset 32769 — the first 32 KB is a system area that most tools skip. A truncated image has no signature at all and looks like a broken file.
Mount rather than extract: mounting keeps Joliet and Rock Ridge names intact, while extraction flattens them.
Where this came from
Notes like this one come out of the file library rather than out of a release schedule. The pages linked above are the entries that were being worked on when the note was written, and those entries are rebuilt with each release of the toolset, so a note can go out of date in a way a format page does not.
When that happens the note stays where it is and gets a correction at the bottom rather than being rewritten, because the point of most of these notes is the order things were tried in. The editors who write them are the ones who maintain the catalogue.