I highly doubt that there was a mutual “settlement” for lack of better words. I agree with some of your statements but I would argue it is a big deal. It’s CGC’s primary service, to trust a third party grader. Honesty, the thing that concerns me the most is that it’s a high grade Golden Age book. If this was a modern, I could over look it (but still be a little worried). For high value books / rare books and for what they charge this is unacceptable (if true).
Edit: Gambling is one thing. A book at this level is not worth the risk for such a small return (relatively $$$ speaking).