The Immunity Syndrome - S2-E18
Continuity mistake: During the teaser, Lt. Kyle is wearing a red tunic, but when Spock returns to the bridge after his examination, Kyle is now wearing a gold tunic.
Continuity mistake: Midway through the episode, a stock shot of the view screen shows Sulu at the helm. When we return to the bridge master shot, however, Sulu isn't there. Styles is the only one at the console, and he's sitting at navigation. The helmsman's chair is empty. (00:32:05)
Revealing mistake: The shot of the castle on Rigel VII seems to be what Pike sees through his eyes, but in the next shot he himself is in the shot.
Continuity mistake: When Scotty awakens in the sick room after being attacked by Nomad, Nurse Chapel has her hands placed on him. In the next shot, when McCoy tells Scotty to take it easy, Nurse Chapel's hands are no longer on Scotty, and in the next shot, her hands are back on him.
Revealing mistake: When Kirk, Spock and McCoy study a diagram that shows various parts of the Nomad probe, the lower right of the diagram reads "Computer Data Banks Recall & Transmition". It should read "Transmission".
Continuity mistake: When the security team is escorting Nomad back to the holding area, he goes his own way. One of the team then says, "Hey Nomad!" and begins to reach for his phaser. But in the next shot, he has already got his phaser out and trained on Nomad.
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: 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)
Revealing mistake: McCoy is knelt down with the rather comically named Flavious Maximus attacking him. On the remastered version it is obvious it is a stunt double doing the part. (00:34:20)
Revealing mistake: Kirk jumps across the burning hot forge to hide from the people approaching him, only problem is that he actually touches the red hot coals with the palm of his hand. Somehow he managed to avoid serious burns. (00:31:15)
Continuity mistake: Mr. Sulu's equipment comes up to aid him at red alert, yet shortly after it is gone. (00:39:00 - 00:40:00)
Continuity mistake: Throughout the entire episode the planet's sky is red, yet during the scenes where the clouds come and lightning strikes, it becomes obvious that they simply used stock footage of Earth's clouds, since the sky is blue. (00:11:50)
Visible crew/equipment: When Vaal is not fed and he starts spewing smoke everywhere, you can see a volcano type firework going off just inside his mouth. (00:43:55)
Other mistake: Kirk and Spock stun two Klingon guards, yet despite being unconscious, the guard on the left jumps from the balcony and lands feet first on the ground. If he were really unconscious he would have simply tumbled down. (00:36:20)
This Side of Paradise - S1-E25
Continuity mistake: Kirk threw a "spore flower" across the bridge and it landed towards the front of the bridge. Later on, Kirk returns to the bridge and despite all the crew being on the planet the flower is gone. (00:28:20)
A Taste of Armageddon - S1-E24
Continuity mistake: The landing party had been apprehended and placed in a locked room under the supervision of a single guard. Spock manages to free them and Kirk knocks out this guard, leaving him in the locked room. Later on in the episode, they return to this very room and somehow this guard is gone. He could not have woken up and walked out because it is a locked room and Kirk took his key. (00:23:45)
Continuity mistake: In the original version, the planet is the same as the one used in "Bread and Circuses", but when the Enterprise leaves orbit at the end, it is a totally different planet, as it is the one used in "Friday's Child".
Continuity mistake: When the Enterprise is trying to push away the asteroid using the deflector, a quick shot of Uhura is shown from stock footage of "And the Children Shall Lead," but she is not in the rest of the episode.
Tomorrow is Yesterday - S1-E20
Other mistake: The Air Force police officer (played by Hal Lynch) was beamed up from inside the records room (after finding Kirk exiting the dark-room) but was returned outside the room... so he was physically transported INTO himself (as opposed to replacing the beamed-up future version at the exact moment and place he was removed as they did the pilot, Christopher).
Chosen answer: If they're in orbit, they're being pulled along by the planet's gravity well, therefore, impulse engines would only be used for minor corrections and would be "on standby" while in orbit, but not active. (Like keeping your car idling without revving the engine and creating plumes of exhaust).
Captain Defenestrator
Thank you for the info.
Movie Nut