Lucy Thinks Ricky is Trying to Murder Her - S1-E1
Visible crew/equipment: When Ricky walks over to the table while he is on the phone with Jerry, a camera is briefly visible on the right hand side of the screen. (00:08:15)
Revealing mistake: When Ricky brings home the psychiatrist, in all the long shots of the living room from the time Ethel walks around the coffee table toward Fred, we can see that all four coffee table legs have been propped up on stone blocks.
Continuity mistake: While Lucy is at Ethel's apartment nervous about leaving the baby with Ricky she's wearing v-strap pumps, then she heads back to her apartment to get her coat and bag, but when Lucy walks into her apartment she's wearing ankle strap pumps instead. (00:16:00)
Continuity mistake: When Lucy handcuffs herself to Ricky we see the style of handcuffs as they phone the locksmith, but when they're both in the bedroom their handcuffs are entirely different, then their handcuffs revert to the original style when the locksmith shows up. Additionally, when Lucy cuffs Ricky's wrist note the direction of the locking bar around Ricky's wrist, but the next morning when the locksmith is with them, the locking bar is around Ricky's wrist the opposite way, which is quite impossible. (00:06:45)
Visible crew/equipment: While Lucy starts taking notes about Ethel, Fred walks in and soon asks, "What's going on this booby hatch," then just as Lucy rushes back to the desk, we can see the end of the set wall and there's some kind of partition in front of the kitchen set. (00:02:35)
Continuity mistake: While Lucy's taking a tally of who everyone's voting for, the writing on the posterboard changes in Lucy's closeups. (00:14:45)
Pregnant Women Are Unpredictable - S2-E16
Trivia: When Lucy's reading the book about infant care, she's holding a baby doll wearing a bonnet in order to learn how to bathe and diaper a baby, and the doll she's using is not just any prop. It's actually one of the show's endorsed products named the "I Love Lucy Baby" doll, which were sold in stores.
Continuity mistake: While Ricky's telling the bedtime story in Spanish to Little Ricky (worth watching just for this darling scene), in the closeups of the baby in the crib, the pillow bumper has an embroidered heart with stick figures, which flips in reverse. Actually, the last closeup of Little Ricky lying down is the normal shot, but all the closeups of the baby sitting up are the flipped shots. (This pillow bumper has stick figures of Lucille Ball and Desi Arnaz, and can be seen in previous episodes). (00:06:40)
Ricky's Old Girlfriend - S3-E11
Continuity mistake: When Fred tells Ricky there's an article in the newspaper about Carlota Romero, there's a closeup of the newspaper's back page with Carlota's photo, but later when Lucy takes the newspaper (the same NY Gazette issue) from Ethel, before she turns it over we can see that the back page photo and layout are different. (00:08:30 - 00:10:20)
Revealing mistake: Look closely at the Ricardos' new Pontiac convertible. There is no glass within the windshield frame.
Deliberate mistake: In episode "Redecorating" Lucy wins new furniture, then in the next episode "Ricky Loses His Voice" the new furniture's delivered to the apartment, and the new couch has two normal and identical seat cushions. Starting in the next episode "Lucy is Enceinte" until the episode "Lucy Wants New Furniture", in some scenes the couch has the identical short cushions, however, in other scenes one of its seat cushions (depending on the episode, it's either left or right) is much higher than the other. For example, in "Lucy Hires a Maid" the higher seat cushion's on left side while Lucy waits for her lunch, then after Ethel urges Lucy to fire the maid the short cushion's on the left. The uneven cushions are usually seen in scenes with either Desi or another male actor, who sit on the side of the couch which has the higher seat cushion. There are even scenes where both of the seat cushions are the higher ones, such as in "Lucy's Last Birthday."
Never Do Business With Friends - S2-E32
Continuity mistake: In Lucy and Ricky's apartment there are six shutters between the kitchen and living room, a set of three open to the left and three open to the right, but after the washing machine falls off the porch, when Mrs. Trumble's nephew thinks they're all crazy he runs through the back door and we see a set of four shutters on one side. Also note the round knobs are at the bottom corners, when they should be higher up at the center. (The prop shutters that we see through the doorway during the porch's "exterior" shots are identical to the seven shutters that were in apartment 4A, before the Ricardos moved downstairs). (00:22:10 - 00:24:25)
Bonus Bucks - S3-E20
Continuity mistake: After Ricky takes out the extra expenses from the prize money, when starched-up Lucy walks into the office Fred's holding the last dollar bill, and in the closeup of Ethel's and Fred's shocked reactions to Lucy's appearance we see Lucy's hand holding the dollar, but in the next wideshot Lucy's open hand is empty so Fred gives her the dollar. (00:24:35)
Revealing mistake: At Freddie Filmore's radio show, when Lucy steps out from behind the curtain, a bit of the kitchen from the Ricardo apartment is visible behind Lucy; it's the cabinet area with plates and canisters, beside the refrigerator. (00:06:15 - 00:19:40)
Visible crew/equipment: At the very start of the opening shot, when Lucy is at the stove, there's a visible crew member at the right side of the screen.
Hollywood Anniversary - S4-E24
Visible crew/equipment: After Lucy rushes out with the newspaper to tell Ethel about all the movie stars coming to the party, when Lucy returns to the suite and closes the door, we can see the arm of a crew member and a board with "DPI" (Desilu Productions Inc) on it, at the bottom right side of the screen, and a bit of equipment at the top right corner. (00:15:00)
Visible crew/equipment: After Ricky and Juanita's song rehearsal, when they both join Fred and Ethel at the side table and talk about doing an afternoon performance, the shadow of the moving overhead boom and mic is visible on the wall and curtain, behind Fred and Ethel. (00:17:50)
The Great Train Robbery - S5-E5
Revealing mistake: When Ricky and Lucy find their train compartment, while they stand outside their door talking we can see the actor playing the porter peeking out of the next compartment's door waiting for his cue, and in a few moments he opens the door just as Lucy approaches. (00:02:20)
Visible crew/equipment: When Lucy and Mrs. Littlefield bring out the soup and then salad, at the start of the shots just as they leave the kitchen, the shadow of another camera can be seen on the edge of the set's "wall" at the right side of the screen. (00:20:25)
Cuban Pals - S1-E28
Visible crew/equipment: Right after Lucy phones for a cab the doorbell rings, and when she opens the door for Fred the cabbie, the shadow of the moving boom and mic appear on the kitchen door. (00:17:20)






Answer: There is no reason. It's a just a silly plot device, typical of the era. Women characters were often portrayed as making uninformed assumptions or decisions.
raywest ★