All too true these days.
I would be more upset with myself than the seller if I sent a book in to CGC or put it into my personal collection raw without properly inspecting it first.
Part of any hobby/ business venture/investment is to be informed and educated, and even with possessing that knowledge things happen. Usually I absorb any mistakes unless I know I was purposefully deceived, so any compensation on a sellers part is appreciated, especially if a significant period of time has passed since the transaction.