When Norville is carrying Amy into his office, he opens the door with is buttocks, where the sign man is painting his name on the door. When he bends over to lay Amy down, there is no paint on his buttocks. But two scenes later he bends over again, the writing from the door can be seen on his pants.
The price sticker on the hula hoop poster disappears in wide shots of the toy store.
When Norville and Musburger get into the elevator together, the elevator doors open in the middle. When they get out on the first floor, the elevator doors open from one side to the other.
The bottom of Norville's coffee cup is perfectly clean when he lifts it up, but it leaves a ring on the newspaper.
At the start of the film, the coffee-stain-encircled help wanted newspaper classified ad for Hudsucker Industries has a typo with "Personel Department" misspelled with one "n". Yet one minute later when Norville picks it up in the street and looks at it, "Personnel" is spelled correctly.
The invitation is for a fancy dress ball, but it turns out to be a black tie affair. A fancy dress ball is one in which people come in costume.
The newspaper with the headline "Imbecile Heads Hudsucker" is dated Monday, December 19, 1958. That date was on a Friday.
In the end credits there is a paragraph which says:
"The foregoing was a fictional account of the development of the HULA HOOP and the characters bear no resemblance to any real person or business concern. The HULA HOOP was actually developed by the founders of the toy company WHAM-O, a true American success story. WHAM-O was subsequently responsible for the development of the FRISBEE and numerous other toy products."
In reality the Frisbee was introduced first, in 1957, followed by the Hula Hoop in 1958.
"The foregoing was a fictional account of the development of the HULA HOOP and the characters bear no resemblance to any real person or business concern. The HULA HOOP was actually developed by the founders of the toy company WHAM-O, a true American success story. WHAM-O was subsequently responsible for the development of the FRISBEE and numerous other toy products."
In reality the Frisbee was introduced first, in 1957, followed by the Hula Hoop in 1958.
This film takes place in December of 1958. The editor of the Manhattan Argus newspaper , Chief, played by John Mahoney, quips, clearly in jest, that his French poodle is more partial to the pages of the French newspaper, Paris-soir. Jest or no jest by Chief, Paris-soir had ceased publication in 1944, having been banned after the liberation of France because of its collaborationist stance.
According to the Wunderground.com, there was no precipitation in New York City on either December 31, 1958, nor on January 1, 1959.
Neither the Hula Hoop nor the Frisbee was developed as described in the movie. This is intentional artistic license to support the plot. The Hula Hoop was invented by Fred Knerr in 1958. The Frisbee was invented by Walter Frederick Morrison in 1957. Both were manufactured by Wham-O.
Interior shots of the clock from Norville's office show the second hand going clockwise. Since it should be a mirror image, the hand should be going counter clockwise.
The time period of this film is the last month of 1958, i.e., December. Yet, when the Hula Hoop hits the stores, the Toy store shown shows nothing indicating Christmas is only a few weeks away, and all but a few of the boys shown in that sequence are wearing short-sleeved shirts, impossible in a New York December.
In the "clock tower" -Amy is able to magically walk on the scaffolding while wearing stiletto heeled shoes.
When Waring Hudsucker throws himself from the meeting room window he falls 44 floors, 45 counting the mezzanine, would be 520' to 530' with each floor averaging 12', and even if the floors were absurdly tall at 20' would top out at 900' in 30 seconds. While standard free fall with an acceleration of 32 f/s sqrd from a 0 f/s an individual would fall about 14500', which even at the top absurd range would still be over 10000' higher than the fall.
In stock footage of kids enjoying the Hula Hoop the American flag has 50 stars. The U.S. flag had 48 stars in 1958.
In the beatnik club, Duke Ellington's "In a Sentimental Mood"
plays in the background. The scene takes place New Year's Eve 1958, but uses the Impulse! recording from Duke Ellington and John Coltrane, which wasn't released until 1962.
Dr. Bronfenbrenner's film of Norville's psychiatric session begins with a SMPTE Universal leader that counts down from 8 to 2. This type of film leader wasn't developed until the 1960s. The film would have actually had either an Academy leader counting from 11 to 3 with black film in between or one of the brand new (for the late 1950s) SMPTE Society leaders that counted from 11 to 3 but had focusing cross hairs, rather than black film, between the numbers.
One of the microphones at Norville's press conference has a flag that reads "WWOR-TV." WOR-TV didn't add the second "W" until the 1980s.
Near the end of the film, when Norville walks out of the juice bar, one of the album covers hanging on the wall on the right hand side of the screen is Tom Lehrer Revisited (Lehrer Records TL 201). This is supposed to take place on December 31, 1958, however that album was not recorded until November 23 & 24, 1959 (side 1) and March 21 & May 4, 1960 (side 2), and its cover photo was not taken until June 29, 1960. The album was released in the second half of 1960.
When Norville is in the mail-room, telling the old mail-sorter about his invention, Norville holds up the drawing, and you can see Norville's lips are not moving when he says his line: "You know, for kids."
At the "dress-up" ball, the orchestra is playing a waltz. But the dancers on the floor are dancing a tango.
When Norville puts Amy on the couch in his office she keeps speaking, but her mouth doesn't move.
The "Finnish" dialogue between Norville and Mr. Finlandson is gibberish, and sounds more like Swedish or Dutch than Finnish.
When the crossword editor asks about "a six letter word for a condition of the hypothalamus", Amy replies with "goiter". A goiter is a condition of the thyroid, not the hypothalamus.