Continuity mistake: When Paul is dining with his agent at the end, after he puts his book down, he picks up a menu. But when the camera angle changes to face him, his hand is empty.
Continuity mistake: When Buster flies over Annie's house, there's a shot of the house from outside and the roof is covered in snow. The shot from the helicopter, the amount of snow changes, including a couple sections being nearly void of snow. There are also a lot of extra tire tracks. (00:38:00)
Continuity mistake: When Annie is shaving Paul, she doesn't shave his chin, but, a second later, his chin is shaved.
Continuity mistake: During the rainstorm, it shows snow on the roof of the house. The next shot of the rainstorm still has the same amount of snow on the roof - some should have been washed away.
Revealing mistake: When Paul and Annie are getting ready to tap glasses, you can see Annie deliberately knocks over the candle. She moves her hand right into the candle to make it fall over.
Suggested correction: It is implied, though by no means certain, that Annie may have intentionally caused the glass of wine to spill, especially as at this point she already knows Paul has been out due to the direction of the Penguin figurine.
Continuity mistake: When the sheriff looks at the last newspaper article about Annie, the caption reads "There is a higher justice than that of man..." Then when it zooms in on the caption it is switched to "There is a justice higher than that of man..." (The 2nd one matches the Misery book quote). (01:25:00)
Continuity mistake: When Paul complains that the paper smudges, Paul types seven letters on a piece of paper to prove it. In the next scene, we see the word he typed was "smudge" which only has six letters.