Continuity mistake: The Klingon is standing on a hillside above Maab, yet when he fires his phaser, the beam streaks upward. From that angle, he wouldn't have hit anything but sky. Nevertheless, the beam somehow re-angles itself downward so that it hits and kills Maab. (00:46:05)
Continuity mistake: Before the Capellans reach him, the Klingon's body moves into a completely different position, and to a different spot on the ground, than it was in when he first fell. (00:46:10)
Continuity mistake: During the coup attempt, one Capellan fights with the leader and gets stabbed. Before and after he is stabbed, the man's outfit changes entirely (look at the fur scarf, which goes from purple to orange.) His costume also changes color.
Continuity mistake: In a wide shot of the Capellons and the Klingon walking down the hill, the Klingon trips and falls to the ground and picks himself up. Next shot, tight group with Klingon, he is suddenly brushing off his pants.
Suggested correction: After Kras falls, the next shot you see him still on the ground and starting to stand up, although Maab blocks the view of him. The shot cuts to the rocks and then when it cuts back, you see Kras walk up and stand next to Maab, then he starts to dust himself off.
Suggested correction: Why would he not be doing that in the next shot? There is no continuity issue.
Revealing mistake: In the tent after Kirk and friends give up their weapons, there is a small fire in the holder in the center of the room. Although the flames are slightly off center to the camera's left, the are projections of flame light from off the camera's right offscreen.
Revealing mistake: When the delegation of locals approach Kirk's party, the Red-shirt yells "KLINGON!" and goes to fire. As he moves, you can see the outline of the block the alien weapon will stick in.
Continuity mistake: The aging Kirk's hairline has receded considerably. When he ages still more and goes completely gray, however, the receding process inexplicably reverses itself, and he suddenly has much more hair on his forehead than before. (00:34:35 - 00:43:55)
Continuity mistake: Mr Checkov has a rather unfortunate hair styling during the beginning of his role in Season 2. In this episode his hair is normal until the end, where in between being given an order and carrying it out he somehow manages to go and have his hair professionally done and made all bouffant. (00:47:15)
Continuity mistake: The Romulan vessels fire plasma weapons (as seen in "Balance of Terror"), but when they hit the Enterprise they become photon torpedoes.
Factual error: As Kirk, McKoy and Scottie age during the episode, their hair goes from brown to fully grey. Mr. Spock shows this to a lesser extent, but by the end of the episode, he has full streaks of grey. This isn't how grey hair works. It starts from the root and works it way outward over time to the end of the strand. Unless their hair is growing quite rapidly, and then cut to keep it short, they shouldn't have full heads of grey hair.
Audio problem: As Commodore Stocker freezes up on the bridge, before the cut to sick bay, the bridge is shaken by a Romulan blast, but the sound is absent.
Visible crew/equipment: After Garrovick is relieved of his duties, Kirk tells McCoy and Spock to make comments and recommendations in their reports, then Garrovick returns to his quarters. Just as Kirk exits the turbo lift on the bridge, the boom mic is visible at the top, left side of the screen. Then when Kirk apologizes to Scotty, in the next wide shot two pieces of filming equipment are visible at the top of the screen. (00:17:20)
Continuity mistake: At the end, when Kirk and Garrovick are beamed up seconds before the explosion, Kirk is holding his communicator up to his mouth with both hands. But when they finally materialize on the Enterprise, Kirk's hands are down at his sides: no communicator in sight. (00:47:00 - 00:48:10)
Continuity mistake: Dr. McCoy's medical tunic has an engineering patch on it, instead of the science patch it should have.
Continuity mistake: On the planet surface, in the scene where the three security men walk around the rock, Garrovick has his arm up with his phaser. When the camera angle cuts to him alone, his arm is suddenly down.
Revealing mistake: When Kirk and Garrovick are fighting at the end, Kirk knocks him down. As he helps him up, Garrovick leans against a huge boulder and the papier-mache rock moves very noticeably.
Continuity mistake: In the briefing room, Hengist and the Prefect are sitting in chairs against the wall at least a foot apart, with bright overhead lighting that casts no shadows on the wall behind them. When we cut to a two-shot of them, however, they're suddenly shoulder-to-shoulder with almost no space between them, and the lighting changes to cast very dark shadows behind them. (00:28:20)
Visible crew/equipment: During Scotty's testimony, when Hengist agrees to the psycho-tricorder analysis of Scotty's memory Kirk tells Scotty he can step down, and the white tape mark is visible on the floor where Kirk stands. (00:28:20)
Continuity mistake: When Mr Hengist goes on the rampage in the hearing room, Kirk pushes Yeoman Tankris behind him. However, when we see Kirk punching Mr Hengist in the jaw in the next shot, Tankris is missing, and in the shot after that, she is back again.
