No, I think it is the work of many dozens of people, not one person.

It's probable that LLM text was pasted directly into early drafts of the document, and plausible that some of that text survives in the final document.

However, no section of the final document I have looked at reads to me like un-edited LLM output (which is almost always very obvious to me.)

Therefore, I think it is more likely than not that human editors went over the document carefully and rewrote anything that was full of the uselessly punchy sentences or constant over-corrections that hallmark LLM speech.