Inaccuracy in advice? Trust.

I recently had a screw in the tire of my Vette. I took it in instead of removing it myself. If it would leak air quickly I would have had to pull the tire and such. What a pain. I took the car into the local tire shop and when I picked it up I was told that if it would have had a hole (It did not, screw was not that deep) they could not have fixed the tire because it was 6 years old. They will only replace tires of this age. So I did some quick research on the internet when I got home to find out that this advice is questionable. It seems that tire age is relevant to storage and more particular the most common age I find that they suggest replacement is ten years. So will I trust the advice of this shop in the future? Nope.