I've heard a story of the opposite, mislabeled from the manufacturer themselves! They were pressing the buyer to upgrade to a newer, faster MOSFET, but the buye

I've heard a story of the opposite, mislabeled from the manufacturer themselves! They were pressing the buyer to upgrade to a newer, faster MOSFET, but the buyer wasn't interested in dealing with going through the EMC compliance process again, so wanted the older parts. Eventually the seller appeared to relent, and shipped a box of FETs with the older label, but lo and behold the assembled boards failed EMC testing, and it turned out the manufacturer had just labelled their newer parts with the old part number and hoped no-one would notice.