Continuity mistake: The severity of Kelly's wound to the face constantly changes. Some shots it's extremely red and raw, others it's only slightly red. (01:22:00 - 01:22:30)
Factual error: In the scene during the evacuation of the Cedar Hospital, Dr Calder is assessing a patient and uses the defibrillator on him. She puts the paddles in the wrong spots on the chest - right hand one over the abdomen and the other over the left lower chest. As a doctor she should know to put the right hand paddle over the upper right chest. This is important for the normal electrical pathway through the heart to reset and restart normal cardiac activity. (01:27:22)
Continuity mistake: When Roark is running to save his daughter, the camera cuts to his point of view and Kelly is shielding the boy with her back towards Roark, yet in the following shot when Roark goes to grab her she is now standing at a side. (01:28:15)
Continuity mistake: At the end of the film, when Tommy Lee Jones steps out of the rubble with his daughter and the young boy, in one shot Tommy Lee Jones puts his hand around his daughter, in the following shot about 2 seconds later he puts his hand around her again. (01:30:15)
Continuity mistake: At the end it starts to rain and everyone is covered in ash, soot, dust etc. However, after only a few seconds of rain, all the ash, dust and soot have vanished off Roark, Kelly and Amy instantly. (01:32:05)
Continuity mistake: At the end when Emmit tells Roarke, "I could get used to this", he puts the cell phone up to his ear twice. (01:37:30)
Factual error: The volcanic lava in this movie moves incredibly fast in the subway line. This is not only inaccurate, but also ridiculous and unnecessary. Volcanic lava can possibly move faster when in a concealed area that insulates it, but insulated lava cannot move that fast.
Factual error: At the end of the movie, when it's raining, with all of the smoke and ash in the air, the rain would have likely been very acidic. The people probably wouldn't be enjoying the sudden downpour.
Factual error: The entire time the volcano is shown erupting, the volcanic lava is instantly melting everything it touches despite the fact that in real life volcanic lava would not have any human being melting because lava is more dense than water. Also lava in real life cannot instantly melt things. And no object should be sinking if caught in a lava flow.
Factual error: The firemen would have used the "jaws of life" to get the fireman out instead of the fireman jumping up on the side of the firetruck and crawling through the window. The driver was trapped and could not have been rescued without them.
Factual error: When lava engulfs the streets, aluminum light poles do not melt (it has a melting point of 1,212° Fahrenheit), yet entire vehicles with steel frames melt into the flow (steel melts at 2,750° Fahrenheit). Lava reaches around 2,000°.
Plot hole: When they are trying to find a way to stop the lava from going in to the museum, Tommy Lee Jones has an idea to push a bus up against the museum to divert the lava. The plan works but the lava does not melt the bus like it melted Tommy Lee Jones' car or the fire truck. Even though the bus melts later in the movie, it doesn't melt it instantly like it did with the fire truck.
Continuity mistake: After the bus is flipped on its side and Roarke and Barnes stop to rescue a man lying in ash, a tree falls blocking their escape with high flames, forcing a ladder truck to save the trio. When the ladder is unable to be lifted because of the weight and extreme heat, the fireman explains he will have to swing them out instead. The ladder swings in the direction of the flaming, downed tree, but the flames from the tree no longer seem to be a hindrance.
Character mistake: The downed firetruck was referred to as engine 17, however it is actually engine 23.
Factual error: It is impossible for a volcano to form under Los Angeles. The San Andreas Fault traveling through the west coast is a "Transform" fault in which the Pacific plate and the North American plate creates a fault line that only slide past each other. In order for a volcano to form, two plates need to subduct. Because there is no ripping apart or subduction taking place along a transform fault, there isn't any magma formation to lead to volcanoes.
Character mistake: When they're literally watching lava creep down the street Roark says "whatever this stuff is" (something like that). 2 things: 1) how does he not realise it's lava, and 2) although it's weird to have lava in LA, Amy already told him that lava could push through from the tar pits, so he should have been able to figure it out.
Suggested correction: Even if he knows what it is, he is still in denial and just doesn't want to say the name of it, as it's uncomfortable to say.
Factual error: Mount Wilshire is basically a shield volcano in the form of a tall stratovolcano because shield volcanoes only shoot ashes, gas, and lava (and pyroclastics for pyroclastic shield volcanoes). The lava itself behaves as if it was sentient. During the lava geyser scene, small particles of molten lava seem to be falling directly on people despite the fact that no-one was anywhere near it except for Mike, his daughter, and the little boy.
Continuity mistake: When the lava begins spilling from the tar pits, Tommy Lee's SUV is not parked next to the pits, but after the downed firetruck shot, the SUV is now there.
Continuity mistake: As the rescue crew is trying to open the disabled subway train, one man bashes the door just below the handle. A second later, he draws back to hit it again, and the door is undamaged from the first blow.
Continuity mistake: After losing her partner, Amy is above ground, taking off the equipment. As she does, her jacket goes from wide open and half off to almost closed in a second.
