a couple of random points
we all know grading is subjective, it is just a number, afterall..if indeed the back cover has been cleaned, and maybe even pressed again, it "could" be a 9.2, right (at least in some folks eyes, folks know I can't grade worth a squat over a 9.0 )
and, unfortunately, not everyone believes in disclosing pressing, to them, it is what it is and supposedly is not a big deal, so if they don't believe in disclosing it, to them, there is nothing wrong (now, if someone asked them if it was pressed, and they denied it, then I think we have problem ethically)... would be nice if folks do, but there is no way to force it, so one should ask if they are worried about it, right?
so one camp would consider this "dishonest" but the other side of the lake is probably perfectly ok with it ...