The Enola Gay that dropped the bomb on Hiroshima was a plane that was stripped of all armor and machine guns to lighten it so that it could carry the heavy payload of the first atomic bomb. In more than one scene the Enola Gay, on its final mission to drop the bomb shows a top turret with obvious machine guns mounted - in other scenes the plane is shown correctly as unarmed.
At one point, Lucy commandeers an Army jeep to drive to where Paul is working. She pulls up to the guarded gate. After her confrontation, she walks back to the jeep. It is now turned around, pointing the opposite way.
When we see the bomb drop out of the bomb bay, it is not the "Little Boy" atomic bomb. It appears to be footage from a drop of Britain's Tallboy bomb which was long and bullet shaped with some animation added such as the nose protrusion of the detonation device. In actuality, Little Boy was blunt nosed like a loaf of bread and the detonation device was inside the bomb not a protrusion on the front of the bomb.
When Lt. Col. Tibbets first gets to Wendover, he is asked for his ID three times. The third MP is wearing a USMC armband. Army military police armbands are only the letters MP, USMC ones are M.P., with the periods.
The name Enola Gay is inscribed on the left (pilot's) side of the real airplane, not on the right as shown in the film.
In the film, Col. Tibbets is told the bomb must explode at 1,600 feet to be effective but the actual detonation took place at approximately. 1,900 feet.
In the first bombing scenes with the B-17's, they actually show a twin engine B-26 dropping the bombs...
When Tibbetts first lands at Tinean, the numbers on the tail of the plane are backward indicating the film was reversed.
Col. Tibbetts is by his plane, and the airman asks about a name, when the plane is shown with the name on it (on the right side) the letters are large, and facing downward. In the next shot, the letters are smaller and the letters are facing upward.
When the B-29 is on final approach for the crash landing, the wheels are up but, when it crashes, the left wheel is down. It's also a B-17 crashing, not the B-29.
During the scene where Tibbets and his flight crew are taking off for the test flight where the plane has been deliberately overloaded by four tons, after Tibbets gives the command to retract the landing gear, the plane is shown taking off with the landing gear still down.
When Lucy Tibbets is leaving her husband, for a moment, she is shown holding her second son, through an airplane window. It is obvious that there is no glass pane in the frame and, in the next jump shot, there are glass window panes on the entire plane, as it pulls away from the camera.
The story is set at the end of WWII, yet the female fashions and hairdos are clearly 1952 styles.
When the B-29s fly over the Golden Gate bridge en route to Tinian, a pre-World War II battleship is shown cruising under the bridge.
Before the B-29 crash landing in Wichita, the plane is shown on approach with tall mountains and desert foliage in the background, neither of which can be found near Wichita, but can be found near Wendover.
When Tibbetts and crew are in the air above Tinian, the island shown is round with a single peak in the center. Tinian is in fact a relatively flat oblong island.
When Tibbets is addressing the men from the flatbed truck, he says they can say they are with a B-29 squadron and that they are going overseas. The men are then sent on leave. The narration points out men who broke security by talking. In Boston, one of the men is asked what he flew, and he says he was flying B-29s. A few scenes later, he is shown arrested for breaking security and talking. Yet, Tibbets himself had given the men permission to say that they were flying B-29s.
Lucy is decorating a cake that says "Happy Birthday Paul" just as he leaves for a meeting. When he returns, he says "Happy Anniversary" to Lucy.