I expect we will see more of this.
As the article states there is no 100% accurate AI detector.
It also doesn’t seem that the professor gave direction that using ChatGPT (or other AI language models) was not allowed. Profs are going to have to address this in their syllabi…e.g., yes you can use ChatGPT/AI if it’s cited as a source, or no use allowed, or whatever.
In classes where AI is not allowed, I would encourage students to run their final essay through an AI detector (plus they would have a history of their writing like the student in the article with the google doc history).