Continuity mistake: When Melvin and Carol enter the restaurant on their trip, a certain song is playing (I can't recall the song). Melvin leaves to buy a jacket, returns, and just after they are seated, you hear the female band leader say, "Here's a special song for...", and it's the same song they played 10 minutes ago. (01:34:00 - 01:38:15)
Continuity mistake: When Melvin is making a phone call outside the Mobil station, the price on the sign above the phone booth is $1.13/gallon. As Carol comes out of the station, the sign behind her shows $1.14/gallon. When the car pulls away from the station, it is back to $1.13/gallon.
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 tells Melvin off for trying to teach Spence manners Spence is standing in the kitchen. When the camera angle changes as Carol walks back to the kitchen counter Spence is standing in the background holding on to the door to the living room. (00:45:15)
Continuity mistake: In the end when Melvin and Carol are kissing, his arm is around her neck. This arm changes from one arm to the other in a split second. (02:12:25)
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 we see Melvin's bedroom, when Simon is looking for the dog, the shelf above his bed is half filled with books and bottles of water. By the end of the phonecall with Carol, the shelf is completely filled. (01:58:15 - 02:01:20)
Continuity mistake: In the restaurant scene with Melvin and Carol, when she is taking her drink from the bar to their table with the help of a waiter, when she first picks up her drink there is very little in it, but when she takes the drink from the waiter and places it on the table it is practically full. (01:33:25)
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: Before Carol takes a bath she tries to help Simon out of his shirt. In spite of being handicapped by his cast he insists on doing it by himself, although with difficulties, but he would never have managed to get out of his black pants into his jammie shorts between shots. (01:41:40)
Continuity mistake: Simon has a rack of pool balls on his coffee table. When Melvin is telling Simon about the bacon, the 2 ball (solid blue) is near the telephone. In the next shot, the dog jumps up to get the bacon and now the 3 ball (solid red) is near the phone. (01:01:20)
Continuity mistake: When Simon's picture is unveiled, the model's hand is now not in either of the positions mentioned in the earlier mistake about the model's hand moving. (00:16:45 - 00:23:25)
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: Melvin is sitting at his desk at home. He takes off his glasses and he stands up to look through the window. When he is about to look outside, the camera shot outside his apartment shows that he takes off his glasses again. (00:50:20)
Continuity mistake: When Melvin is chasing the couple away from "his" table the flowers in the vase on the table are red and orange. When he sits down, there is now a large pink flower in there too. (00:12:10)
Continuity mistake: After the trio's arrival in Baltimore, Carol is in her room placing a call home. When she is first pictured placing the call she has a pager clipped to her jeans. It is gone, never to reappear, in the next shot. (01:30:40)
Continuity mistake: In the scene where the three of them are driving to Baltimore, Carol has a zit on her face. In the next shot it is gone. (01:26:20 - 01:27:30)
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)
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.