[D] How can you tell if a paper was heavily written with the help of LLM?

I’m curious about how people actually identify whether a paper was heavily written (when I say heavily written, I mean maybe 80-90% of any section is generated, not grammatical correction) with ChatGPT, Claude, etc., especially when the writing is fairly polished and sound.

I have passed some of the recent CVPR papers to GPTZero, and grammerly, I found so many papers (especially if the papers are written by not native English speaker) are flagged as a AI written (70+ of the paper content).

Are there specific writing patterns, tone, or structural clues that stand out?