So after much deliberation, I asked my student to run the story through Infinigram (an n-gram attribution engine, which is a fancy way of saying it tells you where a phrase was probably stolen from). Based on my anecdotal experience, LLMs don’t follow genre conventions; they cherry-pick expressions from wherever, genre be damned. Say I am writing literary fiction; I would avoid tropes or hackneyed metaphors like the plague (you see what I did there :P). That kind of writing tends to live on fan fiction sites and the dustier, lower-ranked corners of the web.
Let’s have a little fun. Below you can see a little demo. Don’t forget to click on it. This will show you how LLMs stitch together verbatim expressions from different sources. It’s not technically infringement, because these expressions are not super long, but they are not original either.