The Man Trap - S1-E2
Revealing mistake: Just after Kirk stuns Crater with his phaser, he gets up to get to Crater, when he does he bumps into a heavy stone monument,a prop that shakes visibly on contact. (00:36:58)
Revealing mistake: A straight and level seam connecting the top and bottom halves of the tunnel Spock is crawling through is visible.
Suggested correction: Views of the tunnels made before the creature was wounded by Kirk and Spock appear almost perfectly smooth. It is explained that the creature exudes a powerful acid to dissolve the rock. This tunnel was made after the creature was wounded, so it is logical that the wounded portion of the creature would secrete less acid thus leaving an imperfection as the creature tunnels. This could be a case of incredible attention to detail by the set designer rather than an error revealed.
This correction is too much of a stretch to explain a perfect seam by the wounded Horta. Plus, if the Horta was secreting less corrosive substance, then that area would be less eroded, not more. If attention to detail was paid, then the area would have an outward seam, not an inward one.
Revealing mistake: As the bridge crew monitors Psi 2000 on the view screen, a glitch in the special effects matte makes the planet vanish briefly and then reappear - twice. (00:12:30)
Revealing mistake: When the laser cannon starts firing at the Talosian rockface, a styrofoam block falls and rolls away on the left side of the screen. After a brief shot of the crew, we see the cannon still firing, and the exact same block falls and rolls off screen on the left again. (00:30:15)
Revealing mistake: In the first illusion, Vina runs down the path from the fortress to Pike. When we cut to close-ups, they're both suddenly standing much closer to the building than before, and the fortress has changed color from brownish orange to white. (00:23:50)
Revealing mistake: Due to a poor edit, there's an odd jump cut and a change of lighting just as the Keeper comes out of the elevator on his way to an attempt to steal the laser pistols from the cell. (00:50:40)
Shore Leave - S1-E16
Revealing mistake: Near the end of the episode, the heavy chains restraining the "loose" tiger are visible both around his neck and running across the rocks to the right of the shot. (00:42:35)
Operation -- Annihilate! - S1-E30
Revealing mistake: While Spock and Kirk discuss the phaser resistant creatures, Kirk declares that it may be a trap and to move out. When one of the flying parasitic creatures attacks Spock, in his first closeup just as Spock turns around we can see the thin wire leading from the creature to the right side of the screen, and the wire also casts a shadow on Spock's uniform. (00:18:10)
Shore Leave - S1-E16
Revealing mistake: There is a wooden or straw hut - some kind of man-made structure - visible in the lower-left of the frame behind Kirk and Bones as they walk. (00:12:30)
Suggested correction: They're on a planet where their every thought can be almost instantly created in physical form. Within the context of the episode it wouldn't be unusual to see literally anything in the background. Perhaps one of them was thinking about something involving that structure and it was being constructed for them.
Where No Man Has Gone Before - S1-E4
Revealing mistake: After the ship enters the galactic barrier, when Kirk orders "navigation on automatic" there are flashes of light, and in a closeup of the first console just to the left of the main viewscreen, we can see the special effects material spread across the panel below the controls, for the fire to burn when it explodes. Then it cuts to the wideshot as a second console (near Spock's station) blows up, but in the background that first console is intact - no fire/damage whatsoever (it explodes again in a following wideshot). (00:10:00)
Shore Leave - S1-E16
Revealing mistake: Stock footage turns the single plane strafing Rodriguez and Angela into two attacking planes for a moment. It becomes one plane again when it flies over Kirk and company. (00:33:40)
Revealing mistake: The Horta's round tunnels have perfectly even striations and are obviously factory-manufactured tubes. Acid secreted by an elliptical creature burning through solid rock would not create a perfect circle. The Horta is visibly not chewing, sculpting or smoothing the sides. No acid burning method would leave patterned stripes on the walls, either. (00:18:15)
Revealing mistake: When Kirk and Miri are in the kid's hideout, Kirk is attacked by Louise, the wild woman. After Kirk knocks her off his back, she falls to the ground and tries to get up again, Kirk has to resort to stunning her with his phaser. The blue beam starts coming out then starts coming back towards the phaser before going back out again. (00:26:12)
Tomorrow is Yesterday - S1-E20
Revealing mistake: Traveling towards the Sun and away from the Earth, parts of the Enterprise are missing due to superimposing the model into the current shot. As the Enterprise goes by, one of the warp engines seems to be disintegrating at the rear. (00:42:05)
Revealing mistake: As Spock carries the crewman, the second spear hits a rock. As it does, you can see the Styrofoam chips fly up.
Revealing mistake: As the Romulan ship is tilted, the dust and debris fall straight down, rather than diagonally toward the wall and floor joint.
What Are Little Girls Made Of? - S1-E8
Revealing mistake: When Korby introduces the new android Kirk to Chapel, as the duplicator table slowly turns the edit in the footage can be seen in this shot, just as the real Kirk suddenly vanishes from the space he was in.
Revealing mistake: After Spock finds Gaetano's body he carries him back to the shuttle, and in the interior shot as McCoy and Boma carry Gaetano's body to the back, we can see though the shuttlecraft's doorway the top of the set's blue backdrop.
Revealing mistake: At different points during the Metrons' transmission to the Enterprise, both Kirk and the Gorn pop into the picture a few seconds after the rocky landscape appears. (00:37:00 - 00:37:55)
Revealing mistake: When McCoy is examining Charlie in sickbay, several shots of the diagnostic panel show a clear reflection of Charlie's upright profile. But Charlie isn't sitting up during the exam - he's lying flat on the table. The close-ups of the panel were shot while actor Robert Walker Jr. was either sitting or standing nearby. (00:04:10)
