My bet is that it's "factory miscut", not a true rectangle. My other submission, I got hit with the same thing on two Mantle cards, but since I didn't accept Min Grade Auth on them, they're sending them back raw. Since this submission allowed for Auth cards, they slabbed it anyways.
http://www.net54baseball.com/showpos...postcount=1034
Your card slants left. It's not just diamond cut, the card is sliced at an angle.