people who have supposedly expended large amounts of social capital in one incident or another have not (that I've seen) had their standing raised or lowered permanently, or significantly changed others opinions of them
I had social capital explained differently to me once upon a time, and it has been immeasureably helpful to me, so I'm gonna share.
X ,Y and Z are friends. They do things for one another all the time. Every time X does something for Y and Z, he's depositing into his bank account with each of them. It goes the same for Y and Z. Then Y and Z have a little spat. They each let it go, though, because they've done so much with/for one another over the years that it just doesn't stack up against the capital they've got deposited with one another.
And then X goes crazy. That damned X went off his rocker and he does something really bad. He apologizes the next day, though, and Y and Z let it go. And they let the next thing go, and the next thing go, and so on, until one day, Z realizes that he's done, fed up, tired of it. There's no more capital. The good that X has done over the years no longer outweighs the crazy. Z drops out of the relationship with X. X apologizes to Y, says he's over that, he's back. That gains him a little capital again, or maybe Y's just a little more long-suffering, and the two stay friends for awhile... and then one day, X sneaks in and shaves her cats.
And it's all over.
One, two, even ten incidents over the course of a relationship are pretty much covered by interest. The value of the relationship doesn't go markedly up or down. It's not until the relationship hurts more than it heals that you notice measurable differences; that leads to Y and Z cutting the ties. That line is in a different place for everyone.
I hope no one is annoyed by this explanation. The idea of social capital bugged me when I first heard of it, but when it was explained to me like this, I found it a handy construct for thinking about the way the world works. It also helped me let go more easily, be more like Z than Y. It's not my fault X went crazy. I gave X lots of chances. It's okay to let go because X is hurting me and that's not okay.