Tires: tire replacement or plug hole?, tire replacement, plug hole

Question
Hi, I came out of an appointment to find my car had a flat tire. Mercedes road side changed the tire and found a screw in the middle of the tread part of the tire. The tires are only about 6months old with plenty of tread still on them. When I took the tire to a tire store they said it had been driven on while flat and I needed to purchase a new tire. I have a clue what a flat tire sounds like and there was no indication with the performance or sound that there was a flat tire until I saw it in the parking lot. Can this be true. It is a CLK350 '06. It was the right rear tire which was replaced along with left rear tire 6months ago due to wear by Mercedes dealership.

Answer
Yes, this could have happen.

It could have been low enough to cause damage to the side walls ( driven flat ) and still had enough for you do not know it was flat.

Sorry, but if it has any damage to the inside sidewalls, you will need a new tire.  Just one tire.

Ask to see what they are talking about.  Look at the tire when they take it off.

John