Continuity mistake: Just before the Tyrannosaurus Rex escapes from its pen, it drops a goat's leg on Lex and Timmy's car. When it comes back to attack them, the leg is gone. Then it appears and disappears.
Visible crew/equipment: Watch carefully the scene where the raptors enter the kitchen (that angle where you can see almost the whole kitchen while raptors are coming in from the far away door). As the first raptor enters the kitchen, you can see someone grabbing its tail to hold the puppet-thing steady.
Continuity mistake: Take note when the vehicle starts chasing Sam Neill and the kid down the tree. When it first starts to fall, it smashes a headlight and damages a foglight. In the next shot both lights are undamaged and operational.
Continuity mistake: When Lex and Tim are in the car and the T-rex is attacking them, at one point the T-rex smashes through the roof of the car and the clear roof falls through on top of Lex and Tim. The T-rex breaks it with her teeth, but in the next shot it's whole again.
Continuity mistake: When the lawyer jumps out of the Explorer (just before the T-Rex approaches) he leaves the Explorer door open. In the next two shots the jeep door is closed, but when the T-Rex shows up, the boy moves to the door and closes it.
Other mistake: A live bull is lowered in a sling to feed the raptors in the pen, but when the shredded sling is brought back up, there's no blood on it. How could they have shredded the sling without drawing blood on the bull?
Continuity mistake: When Alan and the kids are about to climb the fence, when he throws a stick at the fence, his hair is messed up, it is sunny and windy. In the next scene his hair is perfectly fixed and it is shady, and it is not windy.
Continuity mistake: When Ellie and Muldoon rescue Ian they leave him in Jeep 10 while they go looking for Alan and the kids, and after the closeup of the water filled T. Rex footprint showing an impact tremor, the next shot zooms in on Ian and we can see the driver's side-view mirror has no writing on it. When they're being chased by the T. Rex, in the shots from behind the Jeep we can see that both side-view mirrors have writing at the top and bottom (shown in closeup "objects in mirror are closer than they appear").
Visible crew/equipment: In the opening scene, a velociraptor is being introduced into the park from a shipping container. The velociraptor runs into the gate as it opens, knocking Jophery off the top; he falls to the ground and is attacked. As he falls, two hands come in to break his fall and prevent him from hitting the camera or hurting himself.
Revealing mistake: When the T-Rex has a raptor in its mouth at the end, the raptor disappears completely from the T-Rex's mouth for one frame. It's just after it's picked up - the T-Rex swings it left, then right, and as it swings to its left again the raptor disappears. If you want to be even more precise, there's a slatted/stepped white bit above the door - the raptor disappears about 3 frames after its foot moves above that white bit.
Revealing mistake: After the T. Rex has flipped the Explorer upside down there's a closeup of Ian, and when it cuts to the T. Rex chomping away on the tire while the Explorer moves around, we can see that the acrylic glass roof is attached to the vehicle with thin cable wire - holes were drilled in the acrylic glass roof and sides of the vehicle.
Revealing mistake: While the T. Rex attacks the Explorer that Lex and Tim are in, during the stunt as the acrylic glass roof comes down on the kids in the interior shots, the strip of duct tape falls through the opening and dangles from the roof of the vehicle - presumably the tape was holding the acrylic glass roof in place before the stunt.
Continuity mistake: While Lex and Tim are hiding in the kitchen, just as the Velociraptors come in Lex tells Tim to follow her, and when they turn into the aisle there's a stainless prep unit with no open shelves right beside them at the end of that aisle, but after the closeups of the Raptor's claws, when the kids continue to crawl away that prep unit has oddly vanished - the last unit in that aisle has shelves, and then it reappears when Tim sits under the utensils.
Visible crew/equipment: When the two Explorer vehicles begin the tour and drive past the huge automated wood doors, if we look at the area between the two doors just as the doors are shut we can see someone's arm come down from behind the door on the right, presumably to keep both doors properly closed for the shot.
Visible crew/equipment: After escaping the T. Rex, when Alan and the kids climb the huge tree we can see a bit of what looks like netting at the top right side of the screen and also the set's scaffolding at the left side, then after the scene with Hammond and Ellie in the dining hall, when it cuts back to Alan and the kids we can see much more of the netting behind the tree set, at the top of the screen.
Continuity mistake: After Alan pulls Lex out from the overturned Explorer and the T. Rex spins the vehicle around, in the closeup shot from behind Tim while he's still inside the Explorer, as the T. Rex leans down facing Tim we can see one of the lower front teeth is missing, but it's back in the following shots.