I had not heard that about the Phaistos Disk. But I wonder if the scholar in question understood how simple stamping works? That was what was shown in the old Dragnet shows, where the hammer strikes the tool and leave a mark in the metal.
If an artisan were going to make a few dozen disks, that sort of stamping method is not only easier, but it eliminates errors caused by miscopying. It would make even more sense if the artisan had a shop table of slaves sitting there doing the work. They wouldn’t even have to understand what they were stamping.
The characters (my favorite is the “mohawk”) are basically identical when found twice on the disk, and the mark from the edge of the die was in the clay here and there when the disk was fired. I’d be surprised if no one besides the conjurer (faker) who sold the disks or the services was the only one in the ancient world to come up with the method, not least because the use of seals for stamping the royal signature was known in Mesopotamia.