Corrected entry: When Mort throws the ashtray into the wall the hole looks a lot like a broken heart, but when we see the hole again it's more rectangular.
Corrected entry: The status bar of the MS Word document which can be seen on Mort Rainey's laptop is changing. Shortly before John Shooter arrives for the first time, the status-bar reads "Four days.", in the next scene at the laptop it reads "I have to talk to you". The rest of the document is exactly the same, even the cursor position is unchanged.
Corrected entry: In the scene where Amy's boyfriend is at the gas station with the divorce papers, and is talking with Mort, the gas prices on the two signs read $1.55 and $1.73, but in another shot $1.73 changes to $1.61.
Corrected entry: In the scene where Amy is trying to escape from Mort in her car, we see that the SAAB 9-3 has a manual gearbox. This would mean that after she is pulled out of the car by Mort, the car would immediately stall because her foot is not pressing the clutch pedal after she put it in reverse. The car does not stall and it keeps going in reverse until it smashes against a tree.
Corrected entry: While Mort is watching his wife and her boyfriend through the rear view mirror, you can see the words "objects in mirror are closer than they appear." This warning is only placed on the passenger side mirror, however it is on the driver side mirror in this scene. Though this may be a deliberate allusion or clue to the ending of the film, it is still a reality based mistake.
Corrected entry: There is a problem with Mort getting away with the murders. The first few sentences of Mort's book "Secret Window" tell you that the plot of the book was a man was going to kill his wife and bury her in the garden. Then, after Mort complains to the cops about how someone is accusing him of stealing the idea for "Secret Window", his wife is killed. The cop at the end even mentions how he suspects/knows Mort did it. Reading the first few sentences of "Secret Window" would be plenty to get a warrant to search the obviously recently dug up garden.
Corrected entry: The first time we see the screwdriver (buried in Tom's head) it is buried up to the hilt, but the second time we see it (when Amy looks at it on the counter top) the 'red stuff', actually blood, is only halfway up the metal part.
Corrected entry: When Mort picks up his mail the girl working there says to him, "That's good because I saw what you did." Then she quickly corrects herself. If she really did see Mort do something then why didn't she go to the police? Granted, she might be afraid that Mort might go after her but still, she could have told the police and Mort would be behind bars.
Corrected entry: The setup that Mort has to wait for the magazine to appear in order to prove to "Shooter" that he really did write the story, has several holes. 1)Most obviously, we see that Mort has several copies of all of his books at the country house. A quick look at the first page of the relevant book would have shown which magazine or outlet originally published the story, as is required by copyright law. So all Mort would've had to do is open that page and show "Shooter" something that would have read "This story originally appeared in Ellery Queen, such and such year, etc etc." 2) Barring that, all it would've taken is a quick phone call to the magazine itself and they could've over nighted a copy of that story. Even if we accept what we later find out about Mort and Shooter, there are still way too many unexplored options to make this plausible.
Corrected entry: Mort wakes up late and goes to meet Ken at the diner. He asks the lady at the counter if she saw Ken, she says no. However, we later find out that they really did meet at the scheduled time and Mort killed Ken and Tom. How come the lady at the counter didn't see them?
Corrected entry: The ease with which Mort gets away with 4 murders seems too good to be true. Firstly, why didn't the investigating cops take a look at the freshly dug up ground which was to become his corn patch? With Mort being the only real suspect it's impossible that they wouldn't have dug up the ground or used ground penetrating radar around his house. Secondly, he had to hide no fewer than 3 cars, not an easy task and the conveniently located nearby body of water would almost certainly have been searched by divers. Thirdly, it's unlikely that he could have cleared up all the forensic evidence of the murders around his house such as blood and fibres. Finally, how would he have completely erased all the engravings on the furniture and walls, at least one of which definitely says "shoot her" (across a doorway)?
Corrected entry: The scene where Rainey is steering the Bronco with the two dead men in it over the cliff the camera pans to a shot under the truck, where another vehicle is visible on the other side.
Corrected entry: In the scene where Mort Rainey's ex-wife comes in the house to get him to sign the divorce papers, she sees SHOOTER engraved deeply on the walls. Yet after she is dead and the cop comes to Mort's house the engravings are no longer there. They were very deep and could not be overlooked, so where did they go?