hm, I don't have any other ways to prove it. The thing is - I thought this is something LLM can't write about.
Just imagine a prompt: "Hey Claude, go ahead and come up with idea why GnuCash stores numbers as fractions and come up with an article for HN". I actually tried it and god damn thing came up with something very similar :D
I am a native English speaker, and I find accusations of LLM-writing exceedingly annoying – to the point where I sometimes intentionally write in that style, just so I can hit back with a profanity.