Goof (errors made by characters, possibly deliberate errors by the filmmakers): Despite being referred to as "The French Woman" and having a French last name, Danielle Rousseau speaks French with a heavy Croatian accent.
Goof (anachronisms): During the scenes in the 1970s, all of the spectacle wearing characters have an anti-reflective coating on their lenses (the greenish hued reflection). While these coatings are very common today, in the 1970s they were generally reserved for optical equipment lenses.
Goof (continuity error): In season 1, Charlie says to Jack that he can't swim, yet in season 3's 'Greatest Hits' it shows that his dad taught him how to swim when he was young. He also swims to the Looking Glass station with no problem.
Goof (anachronisms): At the auction for the "Black Rock"s journal the said it sailed and disappeared in 1845, 20 years before Alfred Nobel applied for his patent for dynamite. Yet the ship supplied dynamite through the series.
Goof (continuity error): When the plane crashes and the people are panicking, we see the same people running in and out of shot repeatedly in the background behind the main characters.
Goof (continuity error): During the flashback sequences for both the pilot and the finale, different characters are meant to be traveling through different sections of the plane, although it appears that, with the exception of business class, the same section was used for filming but with different people. This becomes a problem when spoken lines referring to seat numbers as well as the footage from right before the crash doesn't match at all to the boarding footage in the finale.
Goof (plot holes): Rose is not wearing her husband's wedding ring around her neck as she later says she always does when they are flying.
Goof (factual errors): The Oceanic airplane is supposed to be a Boeing 777, but when you see Jack running through the wreckage you can see that the main landing gear of the plane has only 4 wheels instead of the six a B-777 would have. Also, when Kate, Jack and Charlie reach the front section of the plane, in several shots where you can see the instruments of the cockpit, there are 3 engine indicators instead of the two a 777 would have
Goof (errors in geography): The numbers as coordinates actually take you to a place in central Africa.
Goof (continuity error): In his flashback, Charlie runs from the flight attendants to the front of the plane and locks himself in a bathroom. During the turbulence, he leaves the bathroom and straps himself in a business class seat. We later learn that the front section of the aircraft (business class) separated and landed somewhere in the jungle, yet Charlie is a fuselage-section survivor on the beach.
Goof (continuity error): When Jack uses his tie in the first scenes, you can see he is still wearing it in the next shot.
Goof (revealing mistake): When the scene where the engine explodes is slowed down a black object can be seen flying down and hitting the engine. While some fans believed that this may have been the Monster destroying the engine, the producers confirmed that it is merely a CGI rendering error and that what was meant to be debris flying away from the exploding engine instead became an object hitting it.
Goof (continuity error): In the opening sequence, after Jack removes his bloody undershirt, Kate sews up a large wound in his back. Yet, later, in the cockpit scenes, not only is Jack's rainplastered, semi-transparent undershirt pristine white, it (and his back) is perfectly smooth - no bandages, no stitches.
Goof (continuity error): During the flashback sequences for both the pilot and the finale, different characters are meant to be traveling through different sections of the plane, although it appears that, with the exception of business class, the same section was used for filming but with different people. This becomes a problem when spoken lines referring to seat numbers as well as the footage from right before the crash doesn't match at all to the boarding footage in the finale.
Goof (continuity error): During the flashback scene where Charlie is in the bathroom, he opens a bag of heroin that was closed with a yellow rubber band. While he is taking pinches of the drug and rubbing it inside his mouth, the rubber band goes from being loosely over the first two fingers of his left hand, to being wrapped twice around his index finger, back to being loosely over the first two fingers again.
Goof (continuity error): After Sayid and Sawyer finish fighting, Micheal hands Jack a pair of handcuffs. After that, while Sawyer is shouting, you can clearly spot that in one scene his sleeves reach his wrists, then its folded, then it's back till his wrists. They used 2-3 shots to make one scene.
Goof (factual errors): The farmer tells Kate that he saw her photo in the post office, and that her capture would result in a $23,000 reward. Australian wanted posters are usually in the police station (post offices never have them), and normally do not specify rewards.
Goof (continuity error): In the car-chase flashback, the red truck flips over, off the hill and the tailgate breaks off. The next scene shows the truck in upright position, with the tailgate still on.
Goof (continuity error): The bandage on the marshal's head disappears once between cuts after Michael pushed him back on the ground.
Goof (continuity error): When Locke finds Vincent, the dog, he ties him to a tree, then walks over to Michael and Walt. As Locke is walking you see Walt's head facing away from his dad. When Locke is talking to Michael, Walt is facing his dad. Then when Locke walks away, Walt is facing away from his dad again.
Goof (continuity error): In flashbacks to the airplane clash, the flight attendant says "The captain has switched on the fasten seat belts sign," but in the first episode she says "The pilot has switched on the fasten seat belts sign" in what is clearly the same message.
Goof (revealing mistake): When Kate is in the car with the Australian farmer, the image was horizontally flipped to appear how Australian cars have right-side drivers and left-lane driving. As the U.S. Marshall's GMC truck pulls alongside, the "C" from the grill logo is visible in the farmer's rear view mirror when its reflection should be horizontally flipped.
Goof (factual errors): In Australlia farms or ranches are called stations; especially sheep stations like the one in Kate's flashback.
Goof (continuity error): When Hurley and Charlie are trying to catch fish with the spear, Hurley's t-shirt changes from being wet all over the front to only wet halfway up his chest.
Goof (incorrectly regarded as a mistake): Locke speaks on the phone to a woman named Helen, whom he offers to take to his walkabout, but she can't get involved with her clients. She also mentions that they had been speaking for only a few months. Later in the series, we find that Locke was romantically attached to a woman named Helen to whom he proposed. This is an attempt by Locke to re-create his relationship with Helen, who rejected his proposal and left him.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): In the flashback to Locke's lunch hour at the box company, he names Norman Croucher as having climbed Mount Everest despite being a double amputee. Croucher was a double amputee, but the mountain he climbed was Cho Oyu (still the world's sixth-tallest) and not Everest.
Goof (continuity error): When Jack and Rose are talking on the beach, the blanket over Rose's left shoulder changes position between shots, being on in one and then off in the next
Goof (continuity error): When Charlie and Hurley are questioning Jack about the water in the tent, two people, a man and woman, walk behind Jack twice in the same direction.
Goof (continuity error): Right after Locke goes to search for water, the camera cuts to Jack running through the woods after he sees his father. Jack has two pairs of cuts on his face from the crash: one on his left temple, the other on his right cheek. During this sequence, there is a shot where Jack turns to reveal cuts on his right temple, a minor flip in the editing process.
Goof (crew or equipment visible): When Jack enters the water to try and save the woman who is drowning in the shot that shows him swimming towards the camera you can clearly see a jet ski or boat keel trail.