There was a person who bought a freshly-graded PSA 9 Rayquaza reverse holo from Emerald, when they got it in it looked fine, but then the layers delaminated and the card looked like it had been water damaged. This happens when people soak cards to try to press out dents, but the delamination can happen weeks to months after grading due to changes in ambient temperature/humidity.
Not mentioned in the original post but my understanding is that the person sent the card back to PSA for a grade guarantee, obviously it did not merit the PSA 9 grade and so PSA paid out in compensation.