Where No Man Has Gone Before - S1-E4
Continuity mistake: As Kirk, Spock and Mitchell exit the lift, Yeoman Smith is by the door and begins to follow, and an un-named guy walks by her and into the lift. In the wide shot of the bridge, the actions of Smith and the crewman are repeated.
Continuity mistake: Initially, the Enterprise orbits Psi 2000 as the planet turns westward. But in later shots, on the bridge view screen, the planet has reversed directions and now turns eastward. (00:04:05 - 00:12:00)
Continuity mistake: In the opening, the crewman gets a few drops of the infectant on his hand, but the reddish mass on the wall remains. On the ship, when the spectral view is shown, the red mass is nowhere to be seen.
Continuity mistake: As Scotty starts prying the panel open, it's with a tool in his right hand, and the thumb of his left. After the cut, he's suddenly holding it in his right hand.
Continuity mistake: When Sulu first emerges on the Bridge, Kirk confronts him, and standing a couple feet from the rapier. A second later, Kirk's a few inches from it.
Continuity mistake: As Christine goes to put the respirator in place, she uses her right hand. After the cut, it's her left that puts it in place.
Continuity mistake: As Bones works on Joe's injury, a red light turns on over his head shining down on the area, illuminating his hair. A second later, the red is gone, then back.
Continuity mistake: The indicators radically change positions when Spock gets on the bio bed.
Continuity mistake: When Sulu confronts the men in the corridor, his epee goes from perfectly straight to having a slight crook, then back to straight when he appears on the bridge.
Continuity mistake: As Joe draws back and stands up, he pulls a knife. First, it's sharp side up, then it's suddenly blade down.
Continuity mistake: When "good" Kirk beams up from the planet, the insignia on his shirt is not there. Then it appears when he's walking with Scotty. (00:03:00 - 00:05:25)
Continuity mistake: When the "evil" Kirk appears, the Enterprise emblem is missing from his shirt. Then later, when he gets the brandy, the insignia is there. (00:04:45 - 00:06:20)
Suggested correction: When Kirk and Sulu are on the planet, they're shown not wearing the insignia. When "good" Kirk beams up, he too doesn't have the insignia. We just don't know where it came from, it could have been in their pocket.
The insignia is not removable, it's permanently attached. They wouldn't be able to remove it. The idea of a removable insignia wasn't introduced until STTNG.
While it might have been sewn on for production purposes, I saw this episode as indicating it was removable given the fact that they weren't wearing one on the planet. Plus, there have been other officers whose insignia is not sewn on in TOS.
Continuity mistake: All during the episode there are scratches on the left cheek of the "evil" Kirk. When the "Good" Kirk and the evil Kirk confront each other on the bridge, there's a shot where the scratches are on the right cheek of the evil Kirk.
Mudd's Women - S1-E7
Continuity mistake: As the women are beaming aboard in the transporter room, McCoy's uniform switches from the standard blue tunic to his short-sleeved medical smock and back again between shots. (00:05:55)
Mudd's Women - S1-E7
Continuity mistake: During Mudd's hearing Eve's sitting in the chair beside Mudd, but when Kirk states that the hearing is closed and that Mud will be handed over to legal authorities, in the wideshot Eve's chair is empty, but in the next closeup Eve is still sitting in the chair. (00:18:15)
Mudd's Women - S1-E7
Continuity mistake: Kirk's says that it is Stardate 1329.8 in his opening log entry when the ship is in pursuit of Mudd's vessel. But after Mudd and the women have been brought aboard, Kirk's next log entry says that it is Stardate 1329.1.
Mudd's Women - S1-E7
Continuity mistake: In the briefing room, after Mudd is forced to give his real name, the screen lights up with his record of offenses. In the picture, his image has the ear bauble on the right ear, but he wears it on the left.
What Are Little Girls Made Of? - S1-E8
Continuity mistake: When the android Kirk boards the Enterprise and takes a "command pack," he walks out and down to the transporter, but he doesn't have the pack in his hand.
What Are Little Girls Made Of? - S1-E8
Continuity mistake: While Kirk's trying to convince Ruk that Korby's creating the same danger just like the Old Ones, when Kirk tells him that humans are full of unpredictable emotions, the closeup of Kirk is a flipped shot (the jumpsuit's blue and green switch sides).
What Are Little Girls Made Of? - S1-E8
Continuity mistake: As Kirk talks to Ruk, a closeup of Kirk shows a few strands of hair down over his left eye. In the regular shot, it's normal.
Suggested correction: This wasn't a continuous shot though, we just don't know where they get the insignia, it could have been in his pocket. Both Kirk and Sulu are on the planet's surface without their insignia. And when "evil" Kirk beams up, he too doesn't have it on, even though later he does.
Bishop73
What possible reason could there be for the Enterprise Insignia, which is stitched to every uniform, to be in 'Evil' Kirk's pocket? No character has done this in any episode of Star Trek. They don't get them from anywhere, they are a part of their uniforms.