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)
Revealing mistake: In the shot immediately following Ellie turning on the circuit breakers when the raptor attacks her, we see a light bulb touching its head. There is smoke appearing where the bulb is in contact with the raptors head, the power has been off for a while the bulb would not be that hot after being on for just a few seconds. (01:39:35)
Revealing mistake: When the Explorers are entering the park through the large wooden gate, during the overhead angle you can see that the perimeter fence isn't continuous. (00:40:00)
Revealing mistake: The T-rex does not leave or make any footprints in the soft mud during the attack on the car.
Revealing mistake: During the whole scene of the T-Rex attacking the Explorers you see an illumination that moves from place to place. Sometimes the illumination is in the deep woods, and then it is behind the dinosaur when it is next to the vehicle. When the T-Rex first walks up and sniffs Tim and Lex's Explorer you can even see the light to the left of Rex's head. Since the power is out, no lights are on except the vehicle headlights and they aren't making that much light. Also, there is no moonlight since it is pouring with rain. (00:58:00 - 01:07:00)
Revealing mistake: In the famous kitchen scene, one of the Velociraptors leaps onto one of the counters and knocks over a metal pot with its left foot. The metal pot passes right through the CGI foot. (01:50:35)
Revealing mistake: When Alan and Tim climb down the tree to escape from the falling car, you can see cables along the bark of the tree below the car as it falls. (01:14:20)
Revealing mistake: When Tim gets electrocuted and falls back from the fence, look closely when he reaches Grant and you will see a red stunt crane in the background.
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: Wile driving away from the dinosaur Malcolm tells the driver to go fast. The stunt driver is very noticeable - he has a bigger head and way more hair than the actor.
Revealing mistake: When Ellie is running to the shed, the same clip of her jumping a tree is seen.
Revealing mistake: The two Jeeps running during the tour are supposed to be automatically moving along the track in the road but several shots reveal there is nothing connecting the Jeeps to the track.
Revealing mistake: When Tim is looking at the 2 cups of water vibrating due to the T-Rex's stomping, you can see a very small dark spot at the bottom of the cup, which is actually the knot of a guitar string that was plucked to create the vibration effect.
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