it looks more like a 7.0 than a 5.0 - hidden flaws?
Not really. Grader's notes indicate a number of small flaws. Apparently, CBCS interpreted those flaws as a 7.0 and CGC as a 5.0. Nothing there that would indicate the CBCS graders overlooked something.
But, yeah, it is a very strong 5.0 to my eye.
Without seeing a BC scan, I can't really say with any certainty but that book looks much better than a very strong 5.0 to me.
What do the graders' notes say?
I see absolutely no reason why that book would grade out at a 5.0.
Here they be:
multiple crease right top of front cover
small tear center of staple
small, multiple tear top of front cover
tear top of back cover
tear with crease right top of front cover
Nothing much going on on the back cover. Just looks like a difference of opinion over what grade a book with these flaws should receive.
This is a great looking book. Definitely more 7.0 than 5.0...