It didn't bring HN down. HN deliberately didn't rely on that server for anything except hosting static content that was also duplicated on this server. I planned in advance for the possibility that the other server wouldn't be usable, by writing the code so that I could switch to serving the same content off news by changing one variable, which I did. As a result service was barely affected.

In short, Pair flaked, but we had in fact planned the system in a way that protected us against it.