There is a secondary metric that has the difference between the W/L points. So a Houston will have a smaller delta and a team like BYU will have a wider one (and so will Texas) since they always seem to beat P5's, and Houston will lose (so they will net zero.) So if they net zero against their own competition, they will not 'earn' the higher points awarded to them, hence, they will not rank higher.

So a win against Houston will only count if Houston tends to win, if they tend to lose, it'll not count.