I'm reading Poker Math that matters by Owen Gaines and I'm struggling to calculate outs in certain situations. For instance, I could not understand fully this example in the book:
Hero: Jh7s Villain: AdQs Board: Ah9sTd
I can see clearly that 4 8's would give Hero a straight. In the book he explains that he disregards the KQ backdoor straight because it villain has a Q. I get it.
On the other hand, there's another possibility that I do not understand why it's not been considered: a J and 7 appearing at the turn and river respectively, thus giving Hero 2 pairs against villain's A's top pair.
In this scenario, when a stronger hand depends on a specific pair of cards, they are not counted as outs ?