Dude is a manipulative creep. He spent years stalking her, love-and-money-bombed her and her family to get her affection, then used drugs to control her until they killed her.
If you think anything he did is remotely normal, I feel sorry for the women in your life.
So what you're saying is that the AI is the artist, not the prompter. The AI is performing the labor of creating the work, at the request of the prompter, like the hypothetical art student you mentioned did, and the prompter is not the creator any more than I would be if I kindly asked an art student to paint me a picture.
In which case, the AI is the thing that gets the authorial credit, not the prompter. And since AI is not a person, anything it authors cannot be subjected to copyright, just like when that monkey took a selfie.