Continuity mistake: In the opening scene, when Jophery falls from the cage, he lands on his front. The shot changes to a wide view and he is now on his back and rolls over to get up. (00:02:40)
Continuity mistake: When we first meet the dinosaurs Alan is sitting in front of a lake. Ellie is standing right in front of him. After the cut Ellie comes to Alan from behind and puts her hands on his shoulders. (00:21:25)
Continuity mistake: When the explorers break down outside the T-Rex paddock, Grant can be seen filling a flask with rainwater out of the door. When the angle changes the door is closed, then the angle changes again and he is still collecting rainwater with the door open (fixed in the VHS Widescreen and "Ultimate Collection" DVD box set versions). (00:59:00)
Audio problem: In the kitchen scene, the instant the first velociraptor hops up onto the counters, it knocks off a large metal pot. There is no sound of it hitting the ground. (01:46:05)
Continuity mistake: When Hammond watches the vehicles leaving the visitor center the first car is passed the main steps. In the next shot of the car, they are just moving past the steps. (00:39:30)
Revealing mistake: When Ellie runs from the Raptor the stunt double who runs for her has on a wig that looks nothing like her real hair. It just looks very fake. (01:35:00)
Revealing mistake: When the baby dino is hatching you can see light from a hole below the egg. This allowed them to push the fake dino through the fake egg shell.
Revealing mistake: In the sequence when Lex almost falls from the hole in the ceiling, she looks straight back up at the camera. Rather than cut away from the stunt double at this point, they actually bothered to CGI the actress' face over the top so they could use the sequence right through. Unfortunately you can tell what's been done. (01:51:40)
Continuity mistake: When the T-rex breaks out, on the first car, the one with the kids in it, only the regular headlights are on. When it goes over the "cliff" all the headlights are on. (01:03:20 - 01:09:10)
Audio problem: When the T-Rex is looking at the kids in the Explorer and suddenly makes her screaming sound, the kids jump and put their hands over their ears. But if you watch Tim, he doesn't make any reaction to the noise for about two seconds, then jumps like it just started. (01:02:50)
Audio problem: In the scene at the end when they're in the ceiling then the raptor hits the roof top so it breaks and Lex almost fell to the ground. Well she's always screaming but look closely at the very moment when she falls, her lips don't fit at all. (01:51:30)
Continuity mistake: When Dennis tries to get the dinosaur to fetch a stick, at first the stick is perfectly straight. Then they show a shot of Dennis from the front, and all of a sudden the stick is crooked. (01:10:05)
Visible crew/equipment: In the scene where the cow is being lowered into the raptor cage, the camera shows the ferns and plants shaking. If you look closely, there is the back of a man in a white shirt shaking the plants. (00:31:10)
Continuity mistake: After being electrocuted, Tim flies down vertically, but Dr. Grant catches him horizontally. (01:39:15)
Revealing mistake: When Dr. Malcolm gets thrown through the toilet door by the T-Rex, it is most obviously a stuntman that lands on the ground and gets covered in palm leaves. (01:04:40)
Factual error: Near the beginning, at the "Montana Badlands" dig site of Drs Grant and Sattler, a large shrub identifiable in several shots is creosotebush, a warm-desert plant that doesn't grow anywhere near Montana. Could this be California? (00:08:00)
Deliberate mistake: When the raptor breaks into the control room and is hopping around the computer workstations, we see sharp, distinct genetic coding projected from a computer screen and across the raptor's face (starting 1:55:50). Aside from the fact that computer displays have never projected focused images onto nearby surfaces, the projected text shown in this scene oddly reads from left-to-right, when it should actually be a flipped mirror-image (right-to-left). Spielberg probably realised this factual incongruity while filming but chose to use the left-to-right text for the sake of audience recognition, given that the multiple lines of "GATC" genetic code were already confusing enough. (01:55:50)
Continuity mistake: While they're in Explorer 5, when Ian shows Ellie an example of "unpredictability" her watch reads 5:00, then when Ellie examines the Triceratops' tongue her watch has sped forward and reads approximately 6:05, and a moment later when Dr. Harding hands Ellie the flashlight her watch has run backwards, and now reads approx 5:40. (00:50:40)
Character mistake: Hammond talks about all the things that went wrong when Disneyland opened in 1956. Disneyland actually opened in 1955. (01:32:10)
Continuity mistake: Just as they start going down the wire into the T-Rex paddock, in addition to the problem mentioned above with the ground level suddenly dropping, take a look at the wire. In the first shot underneath them it's curling up and towards the camera, like it's caught on something, then it changes angle, and the wire's hanging straight down. (01:06:15)
Chosen answer: They all left on the same boat Nedry was trying to get on with the embryos. You can hear Samuel L Jackson's character announce that the boat will be leaving at a specific time and everyone had to be there or be left behind.
Shannon Jackson