We had a nun when I was a sophomore in High school that graded essays on handwriting. Seriously. If it was neat and tidy, she gave it an A. Regardless of what it said! That's how subjective essays are! And, you make an excellent point here.

Why did those 5 students not get busted? Maybe it was just their lucky day when he ran the essays through. Next time they may have been in the same boat as the rest. It's stupid any way you look at it. ChatGPT is causing more problems than its worth to writers. It's not perfected yet.