The Immunity Syndrome - S2-E18
Character mistake: The officer at the helm is referred to as Lt. Kyle, and is named that way in the end credits. Yet throughout the episode, Captain Kirk keeps calling him "Kowel".
Character mistake: When Kirk turns to face Spock and McCoy to introduce them to Sarek, the hangar deck nameplate on the wall is misspelled. It reads "hanger deck".
Character mistake: Mr Seven calls the security guard "Sergeant" but he is a corporal.
Character mistake: Spock expresses amazement that the natives of this planet speak Earth English, however, he and Kirk were both on the bridge when Uhura tapped into the planet's news broadcast and already know that they speak Earth English, and there's no reason to tell McCoy, because he heard it too. Commenting on it would be illogical. (00:07:00)
Character mistake: Kirk is surprised by Spock's behavior, but shouldn't everything about Spock be in his records? Kirk should therefore know about Spock's needs and have planned for them.
