It sounds like the direction"one correct direction" thing isn't real; perhapsreal. However, it's definitely a good idea to stir consistently in one direction, to keep things flowing smoothly (laminar flow) rather than creating turbulence. It's possible that they picked one direction as the standard direction and told everyone to stir that way to make sure it was some kind ofconsistent. But if the idea is that clockwise is actually inherently better than counterclockwise, that sounds like a superstition or silly explanation told to people as a joke.
Chocolate comes out shiny and snappy thanks to a process called tempering. It does involve holding the chocolate at a well-controlled temperature and stirring to promote crystal formation, and it is pretty sensitive. But the chocolate doesn't have any idea what direction it's being stirred. The easiest way to mess it up is by getting the temperature wrong, which could actually involve stirring: if it's a large batch and the heat's only coming from the bottom, the stirring might be helping to maintain the correct temperature throughout the chocolate, and if you don't stir deep enough, you'd ruin the temper. Stirring too vigorously (especially if you're pulling in air and cooling the chocolate down) could also cause problems - and this includes things like reversing direction and creating a bunch of turbulence.
With a big batch, if you discovered bad tempering once it'd cooled, I could easily imagine it'd take hours trying to gently reheat and retemper it. And it really is finicky - if you don't know what you're doing, you can completely mess it up and have no idea what you did wrong. I can easily imagine jokes like this ("oh, the tempering's ruined, must've stirred it the wrong direction"), or superstitions ("I swear if I stir it clockwise it always works"). So this does seem consistent with your friend's story, it's just that it's not really anything to do with what specific direction you stir the chocolate in.