There's no tell. Some people just have an overactive imagination and are hallucinating AI authorship wherever they go. I think the HN audience is especially susceptible to this given the amount of comments like GP. Don't get me wrong, there is certainly AI-slop to go around, but this is just a very well-written article in my opinion. At most, lightly edited. It reads like a human wrote it, but maybe I'm just gullible.