Continuity mistake: When Carol enters Melvin's building soaking wet to tell him she'll never sleep with him, we can see bra straps across her back under her blouse. But at Melvin's door, she's embarrassed to discover that the wet blouse reveals a distinct lack of a brassiere.
Continuity mistake: When Simon comes to Melvin's apartment to tell him that he has found his dog and Melvin tells him not ever to knock at his door, not even when the smell of a decaying body is emanating through the door so that he has to put a hanky to his face because of the stench, the glasses he is holding in his right hand disappear and reappear between shots. (00:07:20)
Continuity mistake: After Melvin orders crabs his tie knot keeps changing back and forth between the striped and the checkered pattern of his tie. (01:35:20)
Continuity mistake: In the scene where Simon is sketching/drawing Carol, he rips off the hand piece of his cast so he can move his hand freely. When they are getting out of the car once they get home, you can see that the hand piece of cast that Simon ripped off is back on his hand and the cast is undamaged. (01:49:30 - 01:54:40)
Continuity mistake: In Simon's sketch, Carol is lying the opposite way to the way she is really lying. (01:49:00)
Continuity mistake: When Melvin asks his publisher if her husband doctor can help Spence her hairdo keeps changing between tucked behind her right ear and falling loose over her cheek. (00:50:55)
Continuity mistake: When Melvin and Frank are talking about taking Simon to Baltimore the flowers on the table are yellow and red. When Carol is reading her note to Melvin, they're orange and purple. The colour isn't off because Carol's top looks the same as before. (01:16:00 - 01:17:30)
Continuity mistake: In the hospital, Jackie goes to give Simon her mirror so he can look at himself, and her green purse is scrunched up under her arm. As the shot changes to a wider angle, the purse is now hanging over her stomach.
Continuity mistake: When Carol apologizes to Melvin over the phone her watch rotates around the wrist while she is holding the receiver. (01:56:05)
Continuity mistake: Carol drives the Saab convertible to Baltimore, and she expresses to pull over the car, the rooftop is down. When Carol actually pulls over the Saab the car has the roof on. (01:26:40)
Continuity mistake: When the movie ends and Melvin kisses Carol, his hand changes position between one frame and another.
Continuity mistake: In the beginning of the movie, when Simon asks Melvin if he has seen his dog, he has a towel thrown over his shoulder which is differently arranged in shots from the front and from the back. (00:02:15)
Continuity mistake: In the first diner scene Melvin sits down and takes off his glasses. He starts fiddling with the button of his breast pocket. When the camera angle changes his hands are somewhere else and the pocket is still buttoned. When it changes again he is putting his glasses into the now unbuttoned pocket. (00:12:20)
Continuity mistake: When we see Carol writing the thankyou note, the page is numbered (23), there are 8 lines of writing on the page and she says she is on the last page. When she is looking up the word 'conscience' in the dictionary, the paper is visible again but it is a different sheet - there is no number and there are only 4 lines of writing. It is the page she is about to write on because the last words written are 'have it on my ' - 'conscience' following this phrase makes sense. (01:09:00)
Continuity mistake: When Melvin goes to the restaurant after seeing the psychiatrist and is not served by Carol he bangs on the table and tells the waitress to go and get her. The flowers in the vase on the table change twice in consecutive shots. Pre-bang = yellow, orange and red. Post-bang 1 = white, 2 yellow and red. Post-bang 2 = 2 white and 2 yellow. (00:41:40)
Other mistake: Right at the end of the movie Melvin and Carol walk by a bakery. Suddenly the lights go on showing staff at work like sweeping the floor, indicating that they must have been doing this in the dark. (02:07:55)
Continuity mistake: In the first diner scene we see Carol dealing with some guests and she is not wearing a watch. When she passes by Melvin, who is waiting impatiently for his table, she suddenly has one on her wrist. (00:10:55)
Continuity mistake: After Simon does his imitation of Melvin, he apologizes to Verdell and we see him put his right hand to his forehead - and the same shot from behind him a split second later shows his hand to his mouth.
Continuity mistake: When Melvin gets up to go give Simon some Chinese soup, the clock reads 3:22am. The next scene in Carol's apartment is supposedly later on the same night, yet the babysitter has just arrived, her child is still up, and she and her mom are getting ready to go out for the night (even telling the babysitter that there's pizza in the freezer they can cook later). We know it is supposed to be the same night because in the ensuing scene, Frank tells Melvin he heard he "brought Simon chicken soup last night." (01:04:25)
Continuity mistake: On the way to Baltimore in the car while Jack Nicholson is discussing noodle salad the convertible top is both up and down during different shots of the scene.
Suggested correction: It shows no such thing. In fact Carol has been so thoroughly soaked that both her T-shirt and bra are wet and have become transparent as a result, and her boobs are showing through.
Not true. She has no bra straps showing when at the door talking, wet shirt. When she leaves and turns, the straps are present, wet shirt.