There is some truth to the chain stores not necessarily knowing about your car. But, now that YOU know, you can tell them not to overtighten it because they might strip it.
I worked at one of those Kwik Kar / Jiffy Lube places back in highschool, and the people that worked there longer than I did would always say to me, "That's a ford. it takes a blah blah blah size filter" "That's a volvo. The oil drain plug is hard to get at" They kind of prided themselves in knowing about a lot of cars.
When I took my car to the dealer for an oil change, I also asked them to take a look at a warranty issue problem. The service manager straight up told me that it was a saturday and they only have people there who knew how to do oil changes and wash cars. He basically told me that they were incompitent workers. Even the dealer can make the mistake and overtighten that lug nut and cause a problem. I would be willing to bet that if the dealer DID strip out your drain plug, they wouldn't tell you, but just re-thread the hole and put the drain plug back in.
So, after all that....... Mistakes can happen anywhere.