Posted By:
CoreyRS.hanus"PSA guarantees that all cards submitted to it shall be graded in accordance with PSA grading standards and under the procedures of PSA."
Those words, as posted by Tom, are part of PSA's guaranty. Clearly there is potentially a big loophole -- they can always argue that they graded the card in accordance with their standards and under their procedures, and still missed the alteration. So tough luck.
I don't think though it would end there, though. Inasmuch as many alterations are black and white matters that can be proven as a matter of law, PSA would have a heck of a hard time explaining how they missed such an alteration in this instance but caught it in others. And, even if they could explain, that would be a "win the battle, lose the war scenario" because what they would be arguing is that their standards and procedures are inadequate to catch scientifically detectable alterations.
So, bottom line. If I had altered PSA cards that I could PROVE are altered, I'd return them to PSA and invoke the guarantee.