When Forrest and Jenny are "walking" along past a candlelit vigil in front of the White House, it is noticeable that they pass the same five or six people several times (as well as a couple of the guards at the gate).
Forrest is standing in Jenny's foyer upon entry to her apartment. While they are talking it's possible to see in the background there is an ironing board with the iron laying flat, as if it had been knocked over. While screen shot quickly focuses on the son watching television then quickly back to Forrest and Jenny, the iron has been stood up correctly. Forrest and Jenny had not moved.
During the Protest Rally at the Washington Monument, the tree leaves are not consistent. Behind Forrest on the podium, the trees in the background have no leaves as if it were late autumn or winter. The trees surrounding the reflection pool in front of Forrest are all Green as if it were summer, and in a later scene as Forrest watches Jenny board the bus back to Berkeley, the leaves on all the trees are different colors as if it were the heart of autumn.
The girl behind Forrest and Jenny on the school bus disappears and reappears between shots.
When Forrest is giving his speech about the war in front of the reflecting pool and he runs down to meet Jenny, he walks by the same guy twice.
During the integration of the University of Alabama, the soldiers escorting the black students are depicted as paratroopers from the 82nd Airborne Division. This was actually performed by the Alabama National Guard, after they put under direct federal control by President John F. Kennedy.
The moon is shown as waxing, almost full, and is lit from the top right; an impossible situation at night.
When SGT Forrest Gump receives his LOD (Letter of Discharge), he is only wearing five ribbons - Purple Heart, Army Good Conduct Medal, National Defense Service Medal, Vietnam Service Medal, and the Republic of Vietnam Medal, but is missing the ribbon device for the Medal of Honor for which he was awarded by President Lyndon B. Johnson There is a ribbon as well as the neck medal for the Medal of Honor. His ribbon rack is missing the MOH ribbon.
When Forest is playing football for Alabama, a teammate gives him the ball and he runs for a touchdown. The hand-off was a forward which is illegal on a kicking play. This should have been a penalty and the touchdown would not count.
Forrest is awarded the Medal of Honor, which warrants a salute automatically from all officers and enlisted people who see it on the wearer. Several military personnel fail to salute the Medal when Forrest is walking with Jenny in Washington D.C. The Medal is saluted, not the rank.
Car tire tracks are visible in the segment remembering Nathan Bedford Forrest's Civil War ties with the KKK. However, this footage is taken from D.W. Griffith's The Birth of a Nation (1915), and the CG team chose to leave the goof in.
It has frequently been claimed that the particular Sesame Street (1969) "Bert and Ernie" sketch that Forrest Jr. was watching at Jenny's apartment in 1982 did not air until 1991. The Muppet Wiki, however, did recently claim that the sketch actually first aired in 1980.
Forrest and Bubba clearly state to Lt. Dan upon meeting him for the first time that they are from Alabama, but, shortly afterward, Lt. Dan says, "So you boys are from Arkansas, huh?" (Given how he acts for most of the movie, it's possible Lt. Dan probably wasn't paying any attention.)
When Forrest and Lieutenant Dan are celebrating New Years Eve in the New York City at a bar, Forrest is thinking about Jenny out in California. The ball is dropping on TV and everyone is counting down to the New Year in New York, the scene then cuts to Jenny out in California and she is packing her stuff and leaving the house she's at and as she walks out the door the ball is dropping and counting down to the New Year on the TV, even though it's only 9 pm in California. The TV is showing the ball drop in New York, broadcast nationwide without regard to time zone differences.
The Army Recruiter's top two ribbons on his uniform - Army Commendation Medal and Purple Heart - are out of order. This is not a mistake. Prior to 1985, the Purple Heart was worn in a lower order of precedence, immediately above the Good Conduct Medal, but below the Army Commendation Medal. It now ranks much higher, right below the Bronze Star Medal.
When Forrest is given his discharge papers, he sets down his ping-pong paddle and (computerized) ball to salute the officer. When he picks the paddle back up, he also pretends to pick up the ball, which didn't end up getting animated.
In the montage of Forrest's and Lt. Dan's first successful shrimp catch after the hurricane where they are emptying their full shrimp nets onto the deck of the boat, the shrimp nets are full of headless shrimp. Shrimp caught in nets are complete animals, and they are processed on the boat after they are dumped, at which time their heads are removed. Shrimp boats do not catch pre-processed shrimp from the waters of the gulf.
There's a scene where the Chinese flag appears backwards. Apparently the video frames were reversed in editing.
When Forrest is playing ping pong, the computerized ball starts moving very quickly. If you follow it closely, you can see that it bounces off his elbow at one point instead of the paddle (right before the ball bounces and then seems to hit the camera).
When Lt. Dan falls off the wheelchair, he gets up with the help of his (invisible) legs.
The letter from Apple Computer, dated 1975, uses the 'Apple Garamond' font below the logo. Apple did not use this font before the introduction of the Macintosh in 1984. Until then, the logo featured the Motter Tektura font. The Garamond font itself was only designed in 1977.
When Forrest begins his three-year run, as he passes the barbershop in town, the TV announcer says President Jimmy Carter suffered from heat exhaustion. That happened on September 15, 1979. However, Forrest begins his trip presumably on July 5, 1976, when Carter isn't President yet.
During the 4th of July 1976 celebration scene at Forest's house with Jenny, the fireworks show on the television shows the Statue of Liberty after it was restored. The Statue was restored in 1986.
Using George Wallace's symbolic blocking of the doorway to the University of Alabama (11 June 1963) as a time reference, we know that Forrest is named to the college football All-America team in 1963 where he later meets John F. Kennedy. However, the Associated Press announced their All-America team on 6 Dec 1963 - two weeks after JFK was assassinated. Forrest Gump should never have met JFK.
In a sequence set around 1970, someone is shown reading a copy of USA Today. The newspaper wasn't created until 1982.
As Forrest's mother comes into the room with young Forrest and Elvis Presley, you can see Elvis playing the guitar. Elvis plays one or two more notes after the song stops.
When Forrest and Jenny watch the fireworks, the sound from the fireworks bursting comes exactly on the same time as they appear. There should be a delay as the sound travels over some distance.
Forrest belches after drinking all those bottles of Dr. Pepper but we don't see his mouth move.
While Jenny is angrily throwing rocks at her childhood home she falls to the ground yet you can hear two more rocks hit the house.
Several times during the movie, road signs for US 17 are visible. US 17 does not run through Alabama. It does run thru the SC coast where the movie was filmed.
Through most of the Vietnam scenes we see groves of palm trees that are not found in Asia. In the foreground shots we see the Sabal palmetto (a.k.a. the Cabbage Palm). Sabal is a genus of New World palms, exclusively. This distinctive palm thrives in its native range where the Vietnam parts of the film were actually shot - in South Carolina, which also bears this palm on their state flag. Background matte paintings or computer graphics may fill in related scenes accurately, but the Sabal palms we see betrays the movie's depicted location of Vietnam.
When Forrest decides to end his cross country run in the Monument Valley of Utah, he was running east. He turns, says he is tired and going home, then starts jogging through the crowd heading west toward the mountains, which is the wrong way to get home to Alabama.
The woman on the bench in Savannah tells Forrest to go a few blocks ahead to Henry St. though it is actually behind them.
Forrest and mother live in Alabama but exterior elementary school steps scene was shot at 208 Bull St, Savannah, GA. Building has visible seal of state of Georgia and seal of city of Savannah.
Forrest's doctor may have told him that he has strong legs, but his muscles will have atrophied during the time he was in braces so he would not be as fast as a regular person when he emerged from his braces, never mind much faster, as portrayed in the movie.
If the ramp to the studio door was that icy and slippery, it's unlikely Lt. Dan could have gotten up it in the first place.
It is implausible that Forrest was able to graduate from a university since his IQ is below normal. University level courses are difficult for even those with an IQ in the genius range.
Through out the film Lt. Dan refers to Forrest as Private Gump, despite him achieving the rank of Sergeant at the time of his discharge (signified by the patch on his sleeve).
Prior to the Medal of Honor ceremony at the White House, a newsman announces that four service members, one from each service, are being awarded the Medal. When Forrest bends over to show President Lyndon B. Johnson his wound, there are four members from each of the services with the Medal around their necks, meaning that Forrest makes five.
On seeing Gump on the shrimp boat, Lt. Dan says, "they gave you the Congressional Medal of Honor?"
The medal is frequently, albeit incorrectly, called the Congressional Medal of Honor, stemming from its award by the Department of Defense "in the name of Congress." It is correctly the "Medal of Honor".
When Forrest is in the hospital with a butt injury, he is given back all the letters he wrote to Jenny. On the first envelope, the zip code of her address is 39902. On the second envelope, the zip code is 96602. The third and remaining zip codes are again 39902.
In his narration, Forrest describes Jenny's sexual abuse with childlike naivete: ("He was a very loving man; he was always kissing and touching her and her sisters.") despite being fully aware of its trauma, with an adult understanding. In the exact same narration he goes on to say the police were involved and that there "weren't enough rocks" to destroy the place where it happened.