When Sharkey is sitting on the rock waiting to be rescued, he says "I've been thinking". His hands are down by his belt buckle. The very next moment he hays "I don't think anybody's coming", his arms are crossed over his chest.
When Nelson and Sharkey are looking out at a dinosaur, Nelson calls it a Stegosaurus. The Stegosaurus had a very distinctive double row of dorsal plates and this creature clearly did not. That Nelson knew this Dino name but not what it looked like is maybe a stretch.
During the fight scene between the two dinosaurs, the audio track taken from another movie mistakenly includes a woman screaming at 26 minutes and 4 seconds.
At 44:18, when the captain is chasing Benson, the "island" shakes, and you can see one of the crew with the smoke-making equipment.
Just as Sharkey and the Admiral first sight and run from a dinosaur, the shadow of the boom mic is clearly visible.