Just reading over a summary of the trial in question here, Perry vs. Schwarzenegger. It seems two same-sex couples tried to apply for a marriage license after Prop 8 was passed but were obviously denied. They proceeded to sue the clerks who denied them and a bunch of high officials in California, including Governor Schwarzenegger and Attorney General Jerry Brown.
However, none of the defendants named opted for any sort of defense, with Brown actively stating that the law was wrong and should be overturned. Several groups (mostly Christian organizations) tried to intervene and step up to plate instead because "OH GOD, I CAN'T ALLOW THE GOVERNMENT TO GET AWAY WITH NOT DISCRIMINATING AGAINST THE FAGS!".