Thoughts on a new use of AI

Opposing counsel usually has his laptop open during depositions, no big deal. I recently found out that he is using an AI product that listens to the deposition and suggests follow up questions based on the deponent’s answers. He has never notified me that this program is being used.

Thoughts on this? Is it ethical? Should it be allowed? I’ve had conflicting answers from others and wanted to hear opinions from a larger group.