I'm not saying they didn't. It's just that the title here says "WH releases health report written by LLM" but the article it links to does not claim that. The headline from the article is about the fake citations.

Also, I could imagine that the report, whether drafted by human or not, could have been pasted into an LLM with a prompt like "make this sound more authoritative" and the LLM dutifully added some "citations" because, what's more authoritative looking than citations?