The problem is that unlikely stuff that shouldn’t happen can happen as a result of poorly designed equipment. The first generation of digital audio transceiver chips were a disaster that created clocking errors and ground loops in a lot of gear. As a result, changes in these errors resulting from various cables could make an audible difference. The problem finally got solved after the same poor engineering got applied to video and everybody could see it on a TV screen. We’re still living with people’s distrust of digital cables because nobody wanted to openly blame the problem they missed on the chip manufacturer.