Star Trek

Although Kirk makes a big deal out of McCoy's apparent death, he never even wonders where Mary Teller/Angela Martine has gone or what happened to her. It's uncharacteristic of Kirk to not at least mention something like that, especially when it's a woman.

Trivia: We learn that it took Kirk fifteen years to go from the Academy to being Captain of the Enterprise.

Rodriguez actually calls Mary Teller "Angela" when she collapses after the strafing. This is because actress Barbara Baldavin played a different character, Angela Martine, in the previous episode, "Balance of Terror" and there was some indecision about whether this should be the same character.

They talk about how the planet has no insect or animal life...but nobody seems the least bit curious about how there is what appears to be self-sustaining chlorophyl-based plant life. At least some plants typically require insects to fertilize and almost all require oxygen-breathing creatures to provide carbon dioxide. Shouldn't they have the ship's entire biology department down investigating the phenomenon?

You can also see the shadow of a boom mike when Kirk is chasing Finnegan. It happens when Finnegan is jumping up near the plants, disappears, and then Kirk sprints after him again

A World War II fighter plane appears and makes a strafing run at some of the crew members. As it approaches, it is an American P-51 Mustang. But in the close-up and the shot of it flying away, it is a Japanese fighter.

At the end of this episode, the NCC-1701 on the Enterprise's left nacelle is reversed. (This is removed in the remastered version.)

You can see the shadow of a boom mike on a tree just after the Caretaker appears.

Don Juan attacks Yeoman Barrows and rips her tunic's right shoulder, but when she puts it back on later it's intact.

In the fight with Finnegan, Kirk's shirt is fine. Then Finnegan kicks him in the groin and flips him and the shirt is still fine, but then they immediately cut to a close-up and the shirt is ripped off his right shoulder.

Although everybody always talks about a single Japanese fighter attacking them, in one shot there are two.

The footprints of the White Rabbit it leaves behind are side by side, as if it had hopped. However, when we see it is walking normally - the left-right footprints should be offset.

Sulu fires a "police special" revolver. That weapon can only hold six bullets, but Sulu fires it four times at targets and Kirk fires it three times at the knight - a total of seven bullets.

If you look closely when the tiger menaces Kirk and Spock, you can see the chain holding it in place for the actors' safety.

They never bother to try and send a shuttlecraft down to rescue the landing party, or even mention the possibility.

When Spock beams down, Sulu says, "Someone beaming down from the bridge." In the original series they couldn't beam people off the ship from anywhere except the transporter room.