Blanche is eating a doughnut in the back seat during a motor scene. It goes from one bite missing to half-gone, then mysteriously back to one bite missing again.
When CW offers Eugene back his hamburger, there are several small bites taken out of it. When Eugene's reaction is shown, there is one large bite.
Still on the bed, after Clyde stands up, Bonnie appears with a gun near her face in closeup. The next shot shows her standing up with no gun nearby at all.
When Bonnie first meets Clyde, she's still buttoning up her dress as she's clumping down the bare wood stairs, she's wearing solid shoes with square heels. When you see her walking with Clyde, she has flat ballerina pumps.
Otis Harris takes the gun from Davis holding it by the barrel and passes it like this to Clyde. In the subsequent shot Clyde is holding it by the barrel too, instead of the handle.
The film portrays Texas Ranger Frank Hamer as a vengeful bungler who had been captured, humiliated, and released by Bonnie and Clyde. In reality, Hamer was already a legendary Texas Ranger when he was coaxed out of semi-retirement to hunt down the duo. He never met either of them until he and his posse successfully ambushed and killed them near Gibsland, Louisiana, in 1934. In 1968, Hamer's widow and son sued the movie producers for defamation of character over his portrayal and were awarded an out-of-court settlement in 1971.
In the final scene where Bonnie and Clyde are killed, the Ranger and his deputies are wielding Thompson sub-machine guns. In actual fact, the weapons of choice were Browning Automatic Rifles (B.A.R.).
Bonnie is slumped over near the drivers side of the car when the police finish shooting, but, in actuality, both she and Clyde were in the car when they were shot. Historical pictures show Bonnie slumped against Clyde in the front seat when the shooting finally stops.
When Clyde boasts to Bonnie during their first meeting that he chopped off two toes on his right foot, it was actually his big toe and part of the second toe on his left foot that he severed.
When the Bonnie and Clyde gang takes a break to secretly meet with Bonnie's mother and other relatives, they are outside in the secluded Texas countryside, playing, having a picnic, and enjoying themselves. It is hot outside, and we see parched earth and dry grass. As Clyde talks to old Mrs. Parker, he opens the wrapper to an Eskimo Pie and casually bites into the chocolate-coated vanilla ice cream as he talks. There is no means of refrigeration anywhere and it would have been liquid in that heat.
When C.W. throws a grenade at the armored car, it hits the front fender, breaking in half before the explosion. Since the car is presumably a heavy steel vehicle (which it was in real life), the lightweight grenade shouldn't have broken the fender.
In some chase scenes, tires are heard squealing or skidding as if they are on asphalt when they are obviously on dirt roads.
In the very first scene when Bonnie is flailing around her bedroom, there is an obvious jump in film just as she begins to beat the bed frame with her fist.
The police car that rolls during the chase across the Oklahoma border has an obvious dummy in the front passenger seat, which can be seen as the car rolls. The only other occupant is the stunt driver.
Bonnie's hairstyle in the film is that of a 1960s style, not of the 1930s.
Bonnie pays the grocery delivery boy with modern 1960s-era currency - dollar bills looked quite different during the Depression when the story took place.
Bonnie and Clyde drive into a hay field and are surrounded by modern hay bales tied with twine. The type of hay baler needed to make these bales didn't come into use until the 1940s.
As the gang leaves a bank robbery in 1934, a 1940s Ford fire truck almost hits their getaway car.
After the gang steals Eugene's car, he and Velma turn right, following the stolen car. The sign on the corner is metallic. Metallic road signs were not introduced as street markers decades after the events depicted in the movie. Street signs were usually made out of wood.
When Buck yells, "Shut up!" at Blanche in the shoot-out scene, Gene Hackman's mouth doesn't move.
In the gas station scene where Bonnie and Clyde meet C.W., the lights used for the camera are reflected in the car's chrome fittings, especially on the back of the rear view mirror.
Camera reflected on the group's truck, while Clyde looks for Bonnie in the cornfield.
Before Eugene Grizzard and Velma Davis are taken hostage by Bonnie and Clyde's group, the cameraman's shadow briefly passes over Clyde after pulling up next to his car.
While fleeing Texas law enforcement after a bank robbery, the gang drives into Oklahoma on dry land instead of over a bridge, as one might expect. The substantial Red River forms the boundary between Oklahoma and the parts of Texas (northeast and north-central) in which they were active criminals. The dry-land section of the Texas-Oklahoma boundary lies to the north and east of the Texas panhandle, which is quite far (about 200 miles at the least) from any of their known bank robberies.
During the tourist court shoot-out, the signage states they are in Platte City, Iowa. The shootout actually occurred near Platte City, Missouri, and near the present-day Kansas City International Airport. The approximate location of the tourist court is near Interstate 29 and NW Cookingham Dr. The tourist court has since been torn down.
The character of Ivan Moss is referred to as "Malcolm" by Bonnie in one of the final scenes.
Clyde walks with a limp. At the start of the movie, when he is robbing the general store to impress Bonnie, he runs to the store without a limp.
In the opening credits, the placard giving Bonnie's background mentions that she was born in Rowena, which is in west Texas just outside San Angelo. When Bonnie and Clyde are in the cafe and Clyde is talking about her background, he says, "You were born around east Texas, right?" to which she incorrectly responds, "Yeah."