Ouch. Sorry this happened to you. What made you decide to crack it open in the first place ? If you bought it already cracked out, I would be suspicous of the seller doing some funny business. Historically, CGC has taken the posture that their liability stops after the book is cracked open. Now, CGC is very good at accepting responsibility. If the book was sent to them in the slab for review, I'm sure they would have done something for you. Otherwise, I think all bets are off. However, it can't hurt to contact them. Only asking for a free regrade may be something they can live with. Good luck and keep us in the loop !