Character mistake: After Spike comes out of the evolution device, he asks Iggy "Do you know what the square root of 26481 is?" And then answers "191". 191 squared is actually 36481. (00:47:20)
Character mistake: Kimble has just finished talking on the phone with his lawyer when the cops hear the noise in the background. They figure out the sound is that of an El-Train. They then start to list the different places that have an El. One of the cities they name is Milwaukee - there has never been an El-Train there.
Character mistake: When Nedry is stealing the embryos, an extra "n" is missing on the label "Tyranosaurus".
Character mistake: At the end, when Mitch tells Agent Tarrance that the government can convict the law firm on mail fraud and racketeering, he says he got the idea while he was studying for the bar exam. He actually got the idea from a client earlier in the film when the client was complaining about being over-billed and tells Mitch that every time a bill is mailed through USPS, the firm is committing mail fraud which is a federal offense, punishable by fines and prison.
Suggested correction: This is not wholly correct. Mulholland (the client) planted the seed in Mitch's head, but Mitch realised instantly that it was a federal offense, presumably because he had studied it.
Character mistake: During the "heart attack prank" just before the paramedics get to Frank, Eastwood mistakenly opens his eye before the paramedics wake him.
Suggested correction: It's quite possible that Frank was awakened by the commotion of the EMTs rushing in.
Character mistake: Tony, as a cop, should've known to cuff Rose's hands behind her back. He also apparently doesn't cuff Harriet properly as she's left outside with them dangling from one wrist.
Character mistake: At the start of the car chase scene the dispatcher identifies the stolen car as an '89 Ford, but the Ford LTD Crown Victoria shown in the chase is a 1986 or 1987 model.
Character mistake: Detective Ferguson doesn't follow procedure and give Gloria her right to counsel prior to interrogation.