I'm not sure if you know who jwz is, because I wouldn't put any of those in the realm of impossibility.

But I think it's plausible that he might not've migrated his ancient codebase (not meant as a pejorative, but just factually) to broadly multiuser tooling. If he's maintaining the project locally, I can imagine him having spun up a svn repo way back when and not moving past it. While I love git, it might not have a lot of advantages for his specific use case.