What are the AI tells? The only one I found is redundancy, but it makes sense because this is trying to be approachable to laymen.

Like, you have a great point (the benefit of this approach isn't explained), but that's a mistake humans frequently make.

I read a lot of LLM text every day, so I'm quite good at seeing the cadence, the narrative structures and the phrasing styles. It's not just "it's not just X but Y" or emdashes. I could point them out and you would say oh humans use this trope or phrasing style too, and of course that's true. It's still a tell. But it's pointless to argue about this.