Chris,
What really blows is that in time you probably could have kept submitting the card or had someone else do it and it could have come back graded. If not by SGC then by PSA, it just happens. As most of us realize, the "art" of grading isn't close to being exact. It's subjective and on any given day a trimmed card just might pass.
The part that really sucks is that I bet you could have realized a nice and tidy profit had the card just made it into a holder with a numerical grade.
SGC did this just to see what it felt like to be wrong for once.
