I don’t know how they will adjust the grading, but they’ve gotta do something. If they let the people at the end of the window get away with the cheating and grade as is, the people taking it earlier will get screwed, since I seriously doubt the CAS is going to allow 70+% passrates across all exams.
I don’t know what they will do. It wouldn’t surprise me if they look at raw score distribution by day before finalizing a pass mark. If the distribution shows an extreme pattern, it might affect the resulting pass mark. No matter how skewed, a pass mark varying by day should not be a possibility.