If that's something I'd planned on and intended, and you own the copyright to the painting, you have all sorts of legal tools to go after me -- contributory infringement, collusion, and so on. Still, contributing to a legal violation is not the same as engaging in one.
I suspect an argument can be made that github now incorporates AGPL code generated by co-pilot, and so is AGPL. A fair use argument might be made as well; we've all copied one-liners from blog posts and tutorials, and that's okay. I'm having a harder time seeing a reasonable argument that an ML model is directly infringing just because it can produce a copyrighted work, though.
So I don't think it's a cut-and-dry legal question.
I will give a caveat: Coders tend to read laws much too literally, like computer code. When I was was an obnoxious teenager, I thought I'd found all sorts of contract / license / etc. loopholes in all sorts of legal documents, and I considered myself profoundly clever, thinking I'd outsmarted the lawyers.
Nope.
In college I took law classes, got into the real world, did a few startups, and saw a few legal cases. Court systems have technical rules you need to be aware of, of course (e.g. if you miss a deadline....), but interpreting the law is really grounded in common sense. Common sense is culturally situated, and ours is situated in hundreds of years of case law.