I think a lot of the problems experienced with sick coral have a lot to do with shipping and handling. These are stress factors and stress lowers immunity. We see this in fish. They become vunerable to disease, especially if they've been handled too rough and injured.
There is always the chance of the coral harboring a disease causing bacteria upon collection or came into contact with an infected coral and became suseptible to an outbreak due to the stress the coral's been exposed to through (and it goes exactly like this) being handled, transhipped, handled again, bagged, transported, and handled again, acclimated to a captive environment, handled again, put in a bag, transported, handled again, and finally being acclimated to hopefully a final resting place until it dies. Be very watchful of the way the people at your LFS
handle coral. Even if someone accidently hits the side of the tank with the coral like a flower pot, it can cause a fatal injury.
We, as a people, know so much more about outer space than we do about our own oceans. This lack of knowledge can very well spell the dangers that lay in wait for us.
The oceans surely would swallow us before a rock comes down to smite the planet of it's life.