Star Trek Season 1 Episode 20

It makes no sense that Capt. Christopher and the other guy could be simply beamed back into their own bodies. All the teleporter does is move things; and since the two men's original/past bodies were still there they wouldn't be teleported into them, they would simply be teleported there to coexist along with them i.e. there would be two Capt. Christophers, because both of his bodies (past and present) still exist.

The guard says for Kirk and Sulu to hand him their belts one at a time, and then they both do so and he doesn't tell them to stop or otherwise react to the fact their disobeying his order.

Trivia: Several times throughout this episode they refer to "Starfleet Control" instead of "Starfleet Command."

The Enterprise's chronometer, used in this episode, is mechanical with an odometer-type display. This is a rather primitive device given twenty-third century technology and the Enterprise being a state-of-the-art starship. (A different improved chronometer is used in the remastered version.)

It makes no sense that when they beam Capt. Christopher back into himself that the Enterprise would no longer be there in the sky. That event never changed, so the Enterprise would still be there in the sky, Capt. Christopher would be beamed aboard the Enterprise again and an infinite loop of events would be set into motion where the Captain would see the Enterprise, be beamed aboard, be returned to his plane, see the Enterprise (again), be beamed aboard (again) and so on and so on...

When Spock is doing the countdown for beaming Christopher back into his plane after going back in time again his counting speeds up once he gets to around 5.

Why was Captain Christopher standing up when they beamed him on board? Wasn't he sitting in the jet?

Why do Sulu and Kirk beam down into the Air Force base in standard Starfleet uniforms? On later such missions (Assignment: Earth - Patterns of Force) they have suitable clothing made up, but here they just stand out like sore thumbs. And if they want to be sneaky, why don't they wear black stealth-type clothing?

Kirk describes the technique they're going to use as jamming the engines into reverse and snapping free. The actual visual we see later shows it slowing down, stopping dead, and turning around - it never goes into "reverse."

It seems kind of odd that Spock makes such an obvious mistake as failing to check the impact of John Christopher's disappearance as far as his decendents are concerned - he works out more then 100 variables on the time warp equations while standing around in the transporter room.

When the Airforce guard said to Kirk "I'm going to lock you up for 200 years!" then Kirk said "That ought to be just about right.", actually 200 years after 1968 would be 2168, not 2268.

Captain Christopher was mistakenly credited as Major Christopher in the end credits.