How do you know? Some of the text has a slightly LLM-ish flavour to it (e.g. the numbered lists) but other than that I don’t see any solid evidence of that

Edit: I looked into it a bit and things seems to check out, this person has scuba diving certifications on their LinkedIn and the site seems real and high-effort. While I also don’t have solid proof that it’s not AI generated either, making accusations like this based on no evidence doesn’t seem good at all

Not them but the formatting screams LLM to me. Random "bolding" (rendered on this website as blue text) of phrases, the heading layout, the lists at the end (bullet point followed by bolded text), common repeats of LLM-isms like "A. Not B". None of these alone prove it but combined they provide strong evidence.

You can also see the format and pacing differs greatly from posts on their blog made before LLMs were mainstream, e.g. https://dixken.de/blog/monitoring-dremel-digilab-3d45

While I wouldn't go so far as to say the post is entirely made up (it's possible the underlying story is true) - I would say that it's very likely that OP used an LLM to edit/write the post.