This story reminds me of two very important points I'm always trying to make to my diving and non-diving friends:
1) South Carolina is the shi*t when it comes to diving. I dove with Charleston SCuba when I was down there in 1997 and have been desperately trying to get back ever since. I'd sooner dive there than Florida, that's for sure. great wrecks, lots of big, huge schooling fish, and from what I understand, more different species of sharks than any other state in the Union.
2) There are bigger whites out there than we would all care to imagine, and these occasional sightings are proof of that. We had an 18-footer caught just about a mile outside a major harbor up here in North Shore Massachusetts some years back. Makes you think - how will I get those brown stains out of my drysuit?
One of the reasons I like diving so much in the Northeast is that you never, ever know what's going to come swimming into view. Not knowing exactly what's gonna manifest itself on any given dive is a cool feeling. The earlier post was dead-on: it's not the sharks you can see while diving you should be worried about, it's the ones you can't see.