Tap lightly with a solid object along the chainstay on either side of the chip, and on the chip itself. If the sound differs, walk away.
You can't always see a small crack in CF. There are a lot of shops that may look it over, as has been suggested, but few of them will give you the okay due to liability issues, unless they have the equipment required to perform an accurate inspection.
Technical FAQ: how to find cracks in carbon frames - VeloNews.com