I've seen a lot of AI-generated PRs but I think this one is actually a very unique and interesting case. Most of these are written by novices, don't work, are for less-technical projects, and there isn't any real conversation or changing opinions. This was completely different; it was complex and actually worked, the poster Joel Reymont has 30 years of software experience and not exactly on simple bullshit either (from what I can tell, he was writing device drivers 20 years ago and had an HN account "wagerlabs" since 2008.) There was a real discussion here (the OCaml maintainers had an impressive amount of patience!) and the poster eventually laid out his side coherently with a human-written comment and changed his mind about contributing to OSS with AI.
Don't get me wrong, I still think these AI-generated PRs are a total waste of time for everyone involved and a scourge on OSS maintainers. As it stands today I haven't seen any serious project that's able to use them productively. This PR was still 13k largely incomprehensible lines with several glaring errors. And yet this specific PR is still not like the others!