Incorrectly regarded as goofs: The geography in Costa Rica is such that looming mountain ranges create radically different isolated ecosystems. Some of these isolated systems are pine forests, therefore the vegetation portrayed in the film is realistic.
Continuity: When Ian Malcolm is saying, "Ooh-ahh, that's how it starts", we see Nick Van Owen opening up a silver digital camera. In the very next shot, he's holding the black Nikon.
Factual errors: The SUV manages to pull the armored vehicle backwards despite the fact it is hydroplaning in mud at the same time.
Crew or equipment visible: Reflected in the glass door just before the Tyrannosaurus rex eats a person outside the video store.
Miscellaneous: When Dr. Malcolm sees the arriving helicopters, he holds the binoculars to his eyes backwards.
Revealing mistakes: When Sarah Harding is surrounded by the Stegosaurus, the front creature (the one that swipes its tail at her) is not reflected in the river's water.
Crew or equipment visible: Early in the movie, when Malcolm visits Hammond at his home, a crew member wearing light blue pants is visible in the horizontal mirror in a desk (or something), behind Hammond.
Revealing mistakes: Before Ian Malcolm's daughter begins her somersault in the cabin to knock out the raptors, you can clearly see the wires supporting her.
Continuity: After the trailers go off the cliff and the characters discuss what to do next, Kelly switches position in Ian's arms.
Revealing mistakes: During the trailer sequence, after the safety rope unties, the three characters can be seen being held up by wires after falling.
Continuity: When the truck hangs off the cliff, Ian and Sarah are dangling in front of a closet door, with Sarah holding on to the closet's handle, and Ian hanging directly next to her. Yet, in the next shot where the closet door opens, Ian is nowhere to be seen.
Continuity: When the team first sees the dinosaurs, the photographer takes the digital camera out twice and sets it up.
Continuity: When Ian is at John Hammond's house, he is handed three personnel files. But he is seen with only two files the rest of the scene and we never see him put one down.
Continuity: In Hammond's room, Hammond walks over to his desk and the computer is facing the chair. After he walks back around the desk (after handing Ian the folders), the monitor is facing a different direction.
Incorrectly regarded as goofs: Everyone is surprised when the barge captain reveals that the islands are called Las Cinco Muertes ("The Five Deaths"), even though the name is clearly marked on their map that we see on the wall of the truck. However, it is possible that Nick had simply not seen that map before leaving, and neither Ian or Eddie knew the English translation.
Revealing mistakes: When Sarah reaches up over the edge of the cliff to grab the rope, we see that the rope, which is supposedly holding the weight of three people, is clearly slack.
Continuity: After John Hammond informs Ian Malcolm that an expedition left for "Site B", Malcolm asks, "Who are these four lunatics?" Hammond, however, had not yet informed Malcolm of the number or names of the expedition members.
Crew or equipment visible: Near the end of the movie, we see people run by a store. As the camera tracks closer to the store's double doors, you can see the legs and shoes of the cameraman tracking in with his Steadicam.
Revealing mistakes: When the T-Rex is on his trek through the city streets, a woman backs up her BMW, screaming. However, right before it hits another car, we see the driver is not the same woman, but a person looking back focusing on where they are going, even as the woman's screams are heard.
Continuity: When the Nick Eddie and Ian are looking for Sarah, Ian is holding the tranquilizer gun and Eddie is holding the GPS device. A few shots later they switch.
Continuity: Towards the end of the movie, in the first close-up of the bus going down the street, there is an extra seated just behind the driver. When the T-Rex crashes its head into the bus, the extra behind the driver disappears even though the seat he was on is clearly in shot.
Revealing mistakes: Obvious stunt double for Kelly during her gymnastic move before she kicks the velociraptor out the window.
Incorrectly regarded as goofs: When the Rexes attack Eddie in the car they bite the driver's seat off and it deploys the airbag. A real airbag would inflate much faster and with a different sound than the one in the movie. This is because the deployment of an actual airbag could seriously injure the actor. therefore they created a slower inflating one which accounts for the change in sound as well.
Continuity: Towards the end of the movie Dr Malcolm drives to the lab to rescue the baby T-Rex. While driving into the facility he knocks over a light on the right of the screen, when reversing out the light is standing back up.
Revealing mistakes: In the scene when the trailer flips over the window in the back clearly falls off off the frame and appears to be made of plexiglass.
Continuity: After defeating the raptor in the attack towards the end of the film with Sarah, Ian, and Kelly; a series of events send Sarah tumbling onto the top of a suspended florescent light, which then snaps sending her crashing through a window. In the next shot, Ian and Kelly help her up off the ground - but there is no building anywhere near where she was helped up or a window she could have fallen out of.
Continuity: During the Raptor scene, when Sara and Kelly are hiding from the two Raptors they start to dig a hole by the door. A little while later when the Raptors move to the back of the building, Malcolm runs into the building via the front door but the hole isn't there.
Continuity: The windshield on the SUV, when it is attacked by the T-Rexes, changes from being torn off to being fully attached.
Factual errors: When Dr. Malcolm and Dr. Harding smash through the gate on their way to get "the kid" T-Rex, the misspelled sign says "No Tresspassing".
Continuity: At the end of the movie, the CNN correspondent (on the ship returning to the island) mentions that they are 206 nautical miles from the island and moving at 20 knots, estimating an arrival time of 11:30 am ET. This suggests that it's about 1:30 am ET now, or 10:30 pm PT, yet the scene is set at sunrise (or sunset). Since they're halfway, you may draw your own conclusions about the continuity of their departure time.
Errors in geography: It is impossible for a vessel to crash into downtown San Diego coming from the Pacific Ocean. It would first have to avoid Point Loma, then round North Island on Coronado. The ship carrying the TRex clearly has a straight-on approach on its radar screen; it would have never run into downtown on this course.
Revealing mistakes: After the released Triceratops smashes the conference tent in the InGen base camp, it stands over a flame for a moment before charging to the left. As it passes over a cowering workman there is a clear error in clipping in the CGI tail of the creature as it jumps from being in the background to the foreground over the workman's head.
Crew or equipment visible: When John Hammond is standing beside his bed talking to Ian Macolm near the start of the movie, the cameraman's pale blue jeans are reflected in the bedside mirror moving from right to left as he pans the camera.
Revealing mistakes: When Kelly is doing her gymnastics in the shack before kicking the Raptor out, you can see the hand guards, on her hands, that gymnasts use.
Crew or equipment visible: When Dieter Stark (Peter Stormare) gets lost and slips down a small ravine, a set of hands and blue pads are clearly visible (assisting him) as he comes to a rough stop at the end of his fall.
Incorrectly regarded as goofs: Shortly after Dr. Malcolm discovers that Sarah Harding is on the island. She talks about studying the dinosaurs without any effect whatsoever. Dr. Malcolm states this as impossible due to the "Heisenberg Uncertainty Principle." This principle is related to quantum physics. It has been suggested that the correct principle is the "Hawthorne Effect", which states that a subject group being studied is affected from the simple fact that it is studied. However, the "Heisenberg Uncertainty Principle" includes a theory that the act of measuring something can change the value of whatever you are measuring, which fits into how Dr. Malcolm was talking about Sarah's scientific measurement causing the change in dinosaur behavior, not the kind of environment the dinosaur is in. Also, Dr. Malcolm would be more likely to know the Heisenberg Principle than the Hawthorne because of his line of work in chaos theory.
Miscellaneous: Whenever the ship crashes, the people go on to examine it. Before the T-Rex is released someone goes into the control room and sees a hand on the steering wheel. Nothing in wrong with the windows or room and the T-Rex couldn't have fit his head in the doorway. (However, there was a scene that was cut that showed Velociraptors jumping on the SS Venture and attacking crew-members.)
Crew or equipment visible: After Ian and Sarah have the infant T-Rex in the back seat of the red convertible, as Ian turns into the gas station, in Ian's rear-view mirror you can see a brief reflection of Steven Spielberg with baseball cap directing the scene.
Errors made by characters (possibly deliberate errors by the filmmakers): Sarah Harding is supposed to be an expert on carnivores. Yet during the camping scene she has her bloody coat hanging in the air to dry. Being an expert she should have known that blood in the air attracts carnivores.
Continuity: When the T-Rex escapes from the ship, and into the US Customs center before heading towards San Diego, it walks by a window filled with people acting as is nothing happened - despite a barge crashing into the dock, screaming people, and a roaring T-Rex with thunderous footsteps passing by.
Errors made by characters (possibly deliberate errors by the filmmakers): On the boat going to the island, Eddie tells Ian about the tranquilizer dart's potency (South-sea conch shell). Ian asks Eddie if there is an antidote. Eddie tells him that "he'd be dead before he knew he had an accident." A few scenes later we see Ian holding the tranquilizer gun. Why would he be holding it if he had no knowledge of the drugs potency, or the lack of anti-venom?
Continuity: At the moment of the 2 T-Rex attack, Eddie Carr arrives to the scene to save Ian, Nick and Sarah. Eddie arrives driving the SUV and later he tells Ian that his daughter Kelly is still in the High Hide. How is this possible when we saw that the High Hide required to use the SUV's winch to be lifted? Where did Kelly go?
Revealing mistakes: When Eddie Carr returns to save Ian, Nick and Sarah, he enters the truck using the windshield frame. At the moment he jumps in, he puts his hand on a piece of glass without suffering any damage, giving the idea that it was not a real piece of glass from the broken windshield.
Continuity: At the end of the waterfall scene after the T-Rex leaves, Ian joins Nick, Sarah, and Kelly inside the waterfall yet the next time they are seen, they are already dry with little to no explanation as to how that happened so quickly.
Crew or equipment visible: Before the T-Rex eats the poor guy in town (David Koepp), he tries to enter a building with windows in the front. You can see two people with shorts coming up to the window, the person on the right carrying some equipment. These are definitely the camera and sound guys - bystanders would run away when they see a T-Rex on the street.
Errors made by characters (possibly deliberate errors by the filmmakers): Tembo is supposed to be an expert hunter, yet he regularly carries his rifle barrels-up in the rain. He should be carrying it barrels-down so they don't fill with water.
Revealing mistakes: At the end, the S.S. Venture arrives in port as a derelict with all hands dead. The only dinosaur on this boat is the Rex, contained in the cargo hold. There's no damage to the ship, including the cabin. The scene is a fragment from an earlier version of the film in which Velociraptors infiltrated the ship and killed all hands on board.
Revealing mistakes: As the T-Rex approaches the swimming pool in the suburbs, the water in the pool never ripples, as it does all throughout the rest of the movie.
Revealing mistakes: At one point when Dieter Stark (Peter Stormare) is being attacked by ProCompsagnathi the dinosaurs are seen running down the side of a ravine in the background knocking aside brush. After the last dinosaur has made it's way down, the brush can be seen moving though no dinosaurs are running through it.
Errors made by characters (possibly deliberate errors by the filmmakers): Dieter Stark is an obviously German name but when Dieter is lost and fending off the compys, he curses under his breath in Swedish (Peter Stormare's native tongue).
Errors in geography: CNN correspondent mentioned the ship was 206 nautical miles (206NM) from its destination in Costa Rica, halfway there. Even in a straight line crossing over land, it's over 1300NM from San Diego to Costa Rica, way more than twice 206NM.
Revealing mistakes: In the scene after the rampage by the dinosaurs in camp and the burning vehicle goes flying through the air and into a tree you can clearly see the top of the tree give way and buckle under the weight and then return to its previous position, it does it again at the base as the vehicle falls onto it.
Errors made by characters (possibly deliberate errors by the filmmakers): Sarah mentioned that T-Rex have a large olfactory nerve and that they have to move out quickly, and yet she keeps wearing her jacket covered in the baby T-Rex's blood. Having studied predators for years should have informed her to do better.