In documents made public this week, the utility says a bad weld -- in a pipe installed by a contractor -- caused the explosion that killed eight people and destroyed a neighborhood.
PG&E did take responsibility for a spike in pressure prior to the explosion, but the company says that would not have damaged the pipe.
Democratic Assemblyman Jerry Hill, who represents San Bruno, says the utility is talking out of both sides of its mouth.
"They will say one thing. They will send a nice letter saying that they've paid thousands of dollars for a newspaper advertisement apologizing to the people of San Bruno, apologizing to the state and say how we take responsibility for it, but then at every opportunity, legally, they'll look for a way to get out of that," said Hill.
PG&E also defended its response to the disaster, calling it timely and reasonable.