Near the end of the movie, when TLJ yells on the radio to abort, he's holding the radio backwards and talking into the bottom of the battery. Using a Motorola Saber like that ensures you won't be understood.
When the firetrucks are en route to contain the Lava on Wilshire Avenue, Engine 23 is hit by a "Lava Meteor". When the crews get the concrete barriers into place, the same Engine 23 pulls up to the barriers.
When the fire truck that wrecks is on its side, the light bar on the roof is damaged, and stops working. A scene later, when Roark attempts to rescue the fireman trapped inside, the light bar is undamaged and functioning.
The quake started at 5:14am. At 5:17, we see Roark headed east in the car on Wilshire Blvd. The family dog Max is not with them. It is revealed at the end of the movie that Roark left the dog with Emmett to keep him safe. But there's no way that Roark could've dropped off the dog at the office in that short amount of time. He was see in the doorway with Kelly when the quake started. The times between the events happening and the volcano happening at those points are confused.
At the very end of the movie when Rourke hands the phone to his second-in-command, as he walks away you can see in the background that he puts the phone to his ear. Yet the next shot (close up) he puts the phone to his ear again.
When Dr. Barnes exits the tunnel at MacArthur park and slips off her air tank, her metallic coat slips off her shoulder. It is in place in the next shot, only to be back off her shoulder once more in the next shot.
When Amy heads back to her truck and begins crying after Rachel's death, she reaches up to her face with her left hand, which is gloved. Seconds later when she notices the ash falling, the camera backs away as she holds her hands out to catch it, and the glove has now disappeared.
When Amy comes up out of the tunnel after the earthquake, her hair is flopping all over her face, but when she notices the water in MacArthur Park boiling and turns to shine her flashlight on it, her hair is completely cleared from her face and tucked behind her ears.
During the movie the transit employee sinks into lava after saving the life of the unconscious train operator. Simply put, basaltic lava (~3g/cm^3) is more dense than humans (~1g/cm^3). So if a person where to fall onto lava they would not be able to sink into it, instead they would rest on top and get very badly burned by the 900+ degrees Celsius lava.
Lava is much hotter than indicated, and approaching it as close as shown in the movie would cause certain death. The lava hitting the concrete barriers would cause spalling and disintegration, as occurs when a fuel truck catches fire beneath an underpass, and the paint on the fire trucks would burst into flame.
The K-rail wall was the wrong way round..If you look at the Hoover dam the arch is curved INTO the lake. This provides an arch that strengthens under compression. The arched K-rail wall to stop the lava would have been pushed apart under increasing pressure.
After the first quake, seismologists write down the time as 0914, indicating Pacific Standard/Daylight Time. In real life, seismologists use Coordinated Universal Time (UTC). Depending on the time of year, it should have been recorded as 1714 or 1614.
As the lava flows up to the K-rail dam, it flows around street lights and traffic light poles. Flowing magma is between 700°C and 1350°C. Aluminum, with a melting point of 660°C, would have melted as soon as the lava reached it. A steel chain link fence melts into the flow. Depending on its composition, steel melts between 1050°C and 1550°C.
In the movie, magma rises through the San Andreas fault and hits Los Angeles. The San Andreas fault is a transform boundary, which means the plates move past each other, instead of opening and producing magma. Furthermore, the San Andreas Fault passes through Palmdale, over 35 miles northwest of Los Angeles.
The quake started at 5:14 am. The train appears at 5:28 am. If you look closely at the train, you can see it move up and down. Did the train just stop 19 minutes after the first quake, or did the conductor try starting it again?
When Amy (Anne Heche) and Rachel (Laurie Latham) inspect the tunnel, Laurie straddles the fissure (the crack in the tunnel floor). As she steps on each side of the crack, it bounces. Concrete and earth are solid and do not bounce.