Continuity mistake: Simon's cut on his lip is quite visible in the car on the trip down to Baltimore and on the way back to New York, but it miraculously disappears while they are staying in the hotel in Baltimore.
Continuity mistake: When Carol and Melvin are talking in her restaurant and he is trying to convince her to go to Baltimore, she folds up her thank-you letter, but the subsequent shots show the many-paged letter is still open in her hand in the lower left of the screen.
Continuity mistake: When Carol and Melvin are in the restaurant in Baltimore, she is mad at him and he tells her to sit down. When the camera is on her, her hand is on her hip but when the camera cuts to Melvin, her arm is down over her stomach or in some other position during the scene.
Continuity mistake: After Simon has to dismiss his housekeeper, she is leaving the apartment with her large purse in one hand and several carrier bags in the other. She then lifts her hand, which is now empty, and says, "But who's going to walk Verdell?" There was no time for her to shift or drop her purse.
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: 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 the movie ends and Melvin kisses Carol, his hand changes position between one frame and another.
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: 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.
Continuity mistake: On the trip to Baltimore when Carol tells Simon to wait to tell his story until she pulls over, the top of the car is down. When she's pulling over, the top is up.
Continuity mistake: When Frank forces Melvin to take in Verdell the dog (just after Simon has been beaten up), the camera follows Verdell as he explores Melvin's apartment alone. Melvin's grand piano at this stage has the lid open, but does not have the music rest up. Shortly afterwards, Melvin re-enters the apartment, prepares food for the dog, places the bowl on the floor in the sitting room, then walks over to sit down at the piano. Suddenly the piano's music rest is up. There is no way Melvin has had the time or opportunity to do this during this sequence.
Continuity mistake: When the car pulls over on the way to Baltimore, and Simon talks about his life, Carol's hair swaps from messy to brushed between frames.
Continuity mistake: When the movie ends, the curb is drenched in water, but when the couple starts walking it's completely dry.
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.