Okay, but the answers in [1] look something like:

AI generated. Some of the clues include:

- Most obviously, a failed ISBN checksum

- Other source-to-text integrity issues; for example, the WWF source says very little about Malaysia specifically, only mentions Sunda tigers (Panthera tigris sondaica), and does not mention tapirs at all

- Very short yet consistent paragraph length

- Generic "see also" links, one of which is redlinked

This is not the sort of thing that I pay attention to unless I'm doing detailed research. And even then I'd probably have a bot check these for me, ironically, since it's such a mechanical job. At the very least detecting AI like this requires conscious effort.

Ok, but like, what about [2]?

I can easily tell AI writing. I'm sure plenty goes under the radar, but I can still catch a lot.