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.
Continuity mistake: When the nurse is in her 4x4 vehicle, she looks in her mirror and sees two fire trucks. In the far away shot the first fire engine overtakes her, then when it cuts back to her it's overtaking her again. It's not just repeated for the sake of effect, the radio announcer giving comments of the events is continuous. (00:34:30)
Continuity mistake: When Amy Barnes and Rachel are in the tunnel trying to find out what happened, Rachel falls in the crack of the tunnel, and Amy is thrown back. When it cuts to a different view, Amy Barnes falls or is thrown backwards, yet in the following shot when her hand slips from Rachel's, she falls back again. Also, when she is thrown back by the force, she is thrown back some distance, yet when the smoke subsides she is only about 1 or 2 feet from the crack in the tunnel. (00:27:35)
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.
Continuity mistake: There is a shot of a 'hippy' style car with lots of slogans and messages written all over it, melting, but in a shot much later on, the same car is still in amongst the lava flow, when it should have melted already. You can tell its the same car from the megaphone on the roof. (00:53:20 - 01:00:40)
Continuity mistake: At the Department of Geological Science building, the shot then cuts to a woman saying "I can't". The next is a room full of cameras and a couple of guys standing by the cameras near the doorway, yet in the following shot all the guys have disappeared who were standing by the cameras. (00:06:15)
Continuity mistake: When Roark, Anne Heche and the other woman are in MacArthur Park, Roark walks away and Anne Heche is quite a few feet away from the other woman, but then she is right next to her without barely even moving. Also, when Anne Heche puts her hand on the woman's neck, in the following shot she is taking her hand away, and in the next shot she is taking her hand away again. (00:22:15)
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: Just before the big earthquake, the subway train shown arriving at the Westlake/MacArthur Park station has the number 518 on the front door, however, the train that gets damaged during the earthquake has the number 526 on it. (00:24:30 - 00:33:10)
Continuity mistake: When the train boss sacrifices himself by throwing the train driver over the lava flow, he only just manages to throw him past the flow. But in the following shots where it shows the other rescuers view of the lava flowing toward them, the position of them and the lava coming toward them mean they should be burnt by now. (00:59:40)