Factual error: In the film, the San Andreas fault produces the largest, most sensational earthquake in earth history that levels both Los Angeles and San Francisco, also creating a massive tsunami that also floods the latter. In reality, and according to many earthquake experts, the biggest quake that this fault could produce is an 8.3 and, being a land and not ocean fault, cannot cause a tsunami. Or as consultant to the film Tom Jordan, director of the Southern California Earthquake Center stated, "I gave (the filmmakers) free advice, some of which they took... But much of which they didn't - magnitude nines are too big for San Andreas, and it can't produce a big tsunami."
Factual error: Near the end, Emma Gaines drives a small fiberglass boat at high speed straight through the plate-glass window of a downtown skyscraper. Plate glass is incredibly dense, much more dense than the fiberglass hull of a boat. On high-speed impact, the plate glass might indeed shatter, but the fiberglass hull of the boat would be utterly demolished.
Factual error: We repeatedly see Ray Gaines and his daughter, Blake, swimming and thrashing about in crystal-clear floodwater following the tsunami. But floodwater from a tsunami is invariably inky black with thick, churning silt, sediment and debris. The same crystal-clear tsunami floodwater mistake appears in the movie "2012"
Factual error: This movie makes the same mistake dozens of others have when it comes to tsunamis. When the water is coming into the bay, Dwayne Johnson says 'we need to get over the crest'. Tsunamis don't have crests nor do they act like they are shown here. The water just 'fills' up like in a bathtub.
Factual error: The sunset is in the wrong direction. The sunset is aligned with the Golden Gate bridge which is in a north-south direction. The sun should be setting to the left on the screen, in the pacific ocean. One can also tell that the shadows of the tents at the emergency camp are too short for a sunset. (01:54:25)
Factual error: While driving the stolen truck, the San Andreas fault has cut off the road, with the opposite (west) side of the fault (the Pacific plate) shifting left (southward). In reality, the San Andreas is a right-lateral fault, and the westward Pacific plate shifts northward relative to the North American plate.
Factual error: In the garage of the supposedly earthquake-proof building the walls are all cinder block. This would never be done in real life - the walls would be poured pre-stressed concrete with rebar inside. The same problem in the restaurant that the ex-wife is in - the walls there were also cinder block on the top floor.