There have been many types dupes in the long history of D2 so it is probably true. Just avoid them items for now in trades. Like the Mage Plate Enigma with a 766def is now burned as we cannot see item ID is D2r. There is not a way to know is one is a copy or not. So if you roll and Enigma to trade, make it in a different base or make sure it is ED to the point to not roll 766. The video was sorta messed up when I tried to watch it, though I did see it when he posted it. I do not know if it was taken down or what.
Two identical plates is a little iffy for sure, I mean yeah it happens but wise to avoid it for now.