If vector art was used, or the outlines were placed/adjusted algorithmicly, this is a relatively normal effect caused by a bad path or stray vertices. While it could have been touched up with AI, I'd personally give the benefit of the doubt on this one

I went to the linked account page and it seems like just a consistent quirk in the artist's style. I imagine it'd be difficult to get AI to do that as consistently as it seems. Additionally, he posted the following regarding AI accusations: https://newsie.social/@royaards/115490549503341601

I'd have to vote not AI. Just scanned it really close and looks very much like digital art shading and the disconnected lines are a artistic choice.

I can see where he drew the outline the fill and the shading, looks natural. But it's hard as hell to tell each day.

Think the safest thing artists can do these days is a return to physical media (paint, ink, charcoal). Digital art like this is just so easy for AI to shit out. Not a craft issue, not because it's easy. But because digital is heavily in it's toolkit.

Not AI, just a particular style he's practiced since before AI was a thing

Are you AI slop? I don't know what to think.