The only thing I picked up on this article was that it had to be on a known fault, and if it wasn't, it was on an unknown fault. Since it was small, and in a forest, they weren't looking.
California is riddled with known and unknown faults. There is almost a religious feeling that the next earthquake will be on a known fault. But faults are everywhere! Most likely, it isn't right on the San Andreas, but an 'offshoot'. They aren't allowed to build right beside a known fault, but must offset by x number of metres.
I wonder when they will give up on this, and 'fuzz up' the fault zones a bit. Your chance of damage is more related to your foundation, anyway. There is very little chance of the surface expression splitting your house apart.
(I'm just having some fun with those California guys, don't mind me!)
ps. My readership has suddenly gone way up, but ad clicks are in the toilet. I have mixed feelings.