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 the San Andreas, and it can't produce a big tsunami."
Revealing mistake: In the scene in the lecture hall, the handrail on the steps to the left of stage makes no sense. If built correctly, which they are not, it would indicate there is a wall behind the back row and the steps are just at or below head height of the people there which makes no sense in this auditorium design.