Ur shredded for sure. Yeah, I guess you have more back fat in that area than you 'should' at that bf%. That's just your body maybe - I mean if you've been this lean for quite a few months I'd say that's just where your body holds the last of its fat reserves and you need learn to live with it if you are as lean as you want to be. If you have only been this lean for a short time - I'd say keep doing what you've been doing - be patient - and see what happens after a couple of months. If you're looking for tips on getting rid of it - I'd say you'll figure it out - that's uncharted territory for me (and I plan on staying around 8-10% when I get there).
I think you're probably being too critical of your body. I'd keep doing what you are doing, try to add muscle and see were the fat deposits are after a few months.
There is a huge difference between talking about how to do something and getting it fucking done.