When Harry is getting dressed for his date with Shelly, his brother comes into the room and messes up his hair. Harry tries to straighten it out, but you can still see it sticking up all over. In the very next shot you can see the hair is perfectly combed as if nothing happened.
When Harry Sultenfuss meets Thomas J's mother at the end of the movie, two girls behind them keep changing their places.
When Shelly first meets Vada in the house during their conversation Shelly's hair alternates from straight to wavy throughout the scene.
Vada is in her bed talking to her father and he puts a stuffed animal next to her. In the next scene the stuffed animal disappears.
Vada's teddy bear disappears after her father places it on her pillow.
At the bingo hall, the announcer calls B-39. The Bs in Bingo only go to 15 and the 39 would be an N instead of B.
Harry tells Shelly that he was a popular date in high school because he did "a killer frug." This can't be because the frug was a dance popular in the mid-1960s. The movie takes place in 1972, when Vada is 11. That means she was born in 1961. Her mother died two days after she was born. So Harry was not in high school when the frug was popular.
During the July scenes, a calendar on the wall shows the month beginning on a Sunday. July 1st, 1972 was a Saturday.
When Vada leaves the doctor's office after he says there's nothing wrong with her, she and Thomas J. bicycle away from the town district. A post office mail box is seen bearing the colors of red and blue. The movie is supposed to be in 1972, but the post office changed mailboxes to all blue in 1971. However, it might have taken a while or a small town to catch up.
In the scene when Thomas J is stung by the bees, it was a hornets' nest on the ground he kicked but it was clearly honey bees that came out of the hive.
When Uncle Phil and Vada are talking on the porch swing, Richard Masur is obviously not swallowing the beer he is drinking as his throat does not move.
The film is set in 1972, but in the fairground, the Pirate Ship ride that is shown wasn't invented until 1978.
When the band is playing "The Star Spangled Banner" the American flag is waving the leaves on the trees aren't moving.
When Shelly tucks Vada in she turns out the lights but when Harry comes in to say good night the room, although the lights are out, is very lit.
When Vada and Thomas J. are running away from the bees, Thomas J. says, "Run faster! They're after us!" and Vada responds, "I am running faster!" However, if one watches the scene in slow-motion, it is clear that neither of their lips are moving as they say their lines.
Harry hires Shelly DeVoto despite her having no background in mortuary cosmetics. Not only did he not check her references, he didn't read her resume at all. A master professional like Harry would not be so careless in the hiring process, especially in a business where mistakes cannot happen.
Decoder rings vanished from childhood culture with the arrival of the 1960s. The only way an eleven-year-old in 1972 would know of them would be from some random reminiscence of an adult.
Vada owns a mood ring. The movie takes place in 1972 but mood rings weren't invented until 1975.
Even though the film takes place in 1972, cars that are from the 1980s can be visible in the background.
When Vada lets Shelly in the front door, after she first arrives at the Sultenfuss home, the song "It Never Rains In Southern California" by Albert Hammond is heard playing. The movie is set during the summer of 1972 but the song was not released until October 21st of that year.
The bumper cars are of a far more recent design.
The Name Game song ("banana fana...") was a baby boomer song, released in 1961 and popular among children until around 1963. The Witch Doctor song was released in 1958 and would show up on the radio now and then before disappearing around 1965. Vada and Thomas J. were too young for these songs to have been a part of their childhood.
When Vada bounces her ball along the hall, it only makes the sound of a ball hitting a hard surface, despite landing on a thick woven wool rug at least half of the times she bounces it.
The setting is supposed to be a town in Pennsylvania but there's a palm tree down the street from the funeral home.