It's tough to weigh in with an opinion without seeing what the guy did. But perhaps, as you suggested, he really knows nothing about how to wind CG strings. Trying to see things from Guitar Center's viewpoint, I'd guess than 90% of their business is non-classical guitars. It's probably a lot easier to find techs more familiar with Dalenectros, Epiphones, Gibsons, etc. than with classical guitars. What percentage of the guitar-oriented population really knows much about CGs? Probably pretty small. It's not surprising that they would be unable to hire a really knowledgeable, experienced tech guy for what I'm guessing is not great pay. The guy SHOULD have known how to do the job (or cared enough to do it right, if he knew how), but I can certainly see why a Guitar Center might have trouble hiring the best people.
I don't think Guitar Center sucks. I think they do a pretty good job, considering what they're trying to accomplish, who they are able to hire and who their bread-and-butter customers are.