Sticking to BGS now…
It’s definitely not unheard of for 10s to have flaws. The last two first edition base holo 10s I received back had small scratches that would be tough to spot unless looking at the perfect angle but were definitely present. I expected 9s but I guess they met the criteria. Just made it easier for me to let go of them and buy more 
I don’t think this was a slip up by PSA. The card looks really good.
If you actually measure the centering, it’s probably within gem mint specifications of 40/60.
And you’re being far, far too critical of a scratch on the back of the card no less, that you can barely depict without zooming in 10x.
Looks 10 to me. Maybe the scratch was missed, maybe it wasn’t bad/noticeable enough to lower the grade.
Centering is fine by my eyes. EDIT: I did a lazy measure and it was just good enough.
Thanks guys, will be sending a ton of cards I was hesitent on because of the centering 
It’s definately noticable with the naked eye from a foot away, no need to zoom 10x, just hard to photograph so I made it easier. Believe me I know a PSA 10 is not flawless , I collect sports also and they dont hold a handle to BGS 10s.
You were worried you might receive some mint 9s?