That's a little strange--Personally, if I were a Cervelo owner and took my bike to the shop and they messed it up, I'd at least ask for a replacement... I also don't know of any workstands that would make such a small, round mark in one spot from overtightening a clamp. The story stinks, IMHO.

When you look at it, go over the whole bike very closely, but pay particular attention to the top tube. Make sure it feels smooth and you don't feel any dents or raised areas.

What model Cervelo is it?