Mary,

I don't know. In the documentary Lucy said the pressure from the fault caused the oil to be forced up into the hills, but they didn't discover it until after the earthquake. But its possible someone around there knew. The place where this was filmed was along a dirt access road and the monitoring (seismic) station was just about 100 feet up the hill from there. Someone could have noticed it and told her, but that information may not have been included in the film. But she did say it was as a result of the fault creating pressure, so there isn't any doubt as to how it got there and as she specifically said it was a precursor to the earthquake, they had some way of knowing it was there prior to the earthquake.

Petra