I remember hearing a story similar to this from one of the Worlds biggest collectors, Nat Turner.
He sent a huge value MJ to BGS by mail and it showed delivered but was actually intercepted by a postal worker who then put it on eBay not realizing what he had.
Police caught him, but he no longer sends to BGS via mail amymore. PSA only or hand delivers cards to BGS.
Not BGS’s fault either, but theyd be spewin to miss out on grading some of his acquisitions Im sure