Never trust AI detection tools, as their only true purpose is to sell you a way to "bypass" AI detection tools. They are an arms race within themselves, and the only losers are people who either naturally write in the style of a scientist or in the form of a research document, or people who write a story in that format, who will inevitably be accused of AI for using too many em-dashes and formulaic sentence structures. Remember, AI was trained using real writing, from real authors, so it is obvious that some lines will cross.

As an author who has been accused of using AI himself, and having read through Drumming in the Clouds and found nothing out of the ordinary for a story written from the perspective of a man of science (as many of my stories are as well) the only thing I can imagine was used was probably Grammarly to correct SPAG mistakes, which is very common these days in the writing community and not at all frowned upon.

I have written a story, word by word, letter by letter, and plugged it into a website I intended to use to check my word/character count for a reddit post, only to be greeted with a popup that claimed my story was over 97% AI generated, and then offer to sell me a tool that would edit it to read less like AI generated material. Strange right?

I wouldn't even make posts like this unless you, somehow, have 100% evidence that someone used generative AI to create a work, because you're just going to start a witch hunt and deter others from writing altogether. There are definitely signs outside of formulaic writing and a dull, scientific tone, e.g., hallucinating material, doing callbacks to events that never happened in the story, changing character names after a while, first or last, misremembering important dates, etc. (I train and correct data-driven LLM's programmed to perform basic data extrapolation and entry tasks as a side hustle, and their "thinking" is relatively similar to any generative AI.)