One thing to note.

They were quite conservative in their approach, so the only things that were rejected were from people who had agreed not to use an LLM and almost definitely did use an LLM (since they fed hidden watermarked instructions to the llm's).

This means the true number of people that used LLM's in their review (even in group A that had agreed not to) is likely higher.

Also worth noting, 10% of these authors used them in more than half of their reviews.