Other mistake: When the three fairies are cleaning up the cottage, Merriwether has the broom magically sweep all the dust into a pile, then she makes the pile disappear. Right after it does so, the picture is stuck in a freeze-frame for about half a second.
Other mistake: The Count and the Professor jump into the water to save themselves from the dinosaurs (which can't swim). In the long shots, it appears they are out very far, in at least six foot deep water, but close up, the water they are in couldn't be higher than four feet. What's to keep the dinosaurs from grabbing the two if they're in water that wouldn' come up to the dinosaurs' kneecaps?