When Koenig talks to the older Helena, the regular one can be seen standing directly in front of the door. However, the close ups on her show no door but a large expanse of scenery extending some way into the distance.
In the frontal shots of the children, the girl is clearly shorter than the boy, but in the shots facing Koenig (from behind the children), they appear to be the same height.
When Alan finds the uniform in the cave, he immediately identifies it as belonging to Sandra due to the yellow sleeve. However, the sleeve alone wouldn't mean it was hers as Koenig's Eagle co-pilot, who was also missing at the time, wore yellow as well.
Sandra is kidnapped from inside an Eagle, yet Bergman, Alan and Kano think it is completely safe to sleep outside.
Every time an Eagle lands on the planet, the others already there have moved slightly from where they were before.
One of the Eagles on the planet is very obviously a mock up, probably a cut out photograph, and not a proper model like the other two.
Kano and Bergman's Eagle is shown on the landing pad with the docking tube on the port side, but it launches with the tube to starboard.
A number of insects bit Zienia Merton's legs, and to keep warm she was given brandy- which made her fairly drunk. Bob Kellett insisted the leopardskin dress she wear be an authentic skin which she had to tie on with no underwear, but when slumping against the tree at the end of the chase she kept falling out of it.
When Simmonds is trying to break out of his casket, we can see two aliens in the background. At the end of the scene, one of the aliens turns his head, the other sits up, but they were supposed to be in suspended animation.
At the end of the episode, Zantor's wig falls off as he lays down.
In the alien ship, the floor markings denoting where the actors should stand are visible.
During the crash-landing of the alien ship, Alan's Eagle co-pilot disappears in one shot.
The door aboard Eagle 1 reads "Rescue Eagle 7".
The Eagle docks to the Kaldorian ship on the starboard side, but they enter through the port side.
When they board the Eagle on the launch pad, it is docked on it's starboard side, but it is entered through the port side.
As Alan's Eagle leaves the alien ship, the Eagle had already begun to move before the thrusters fired.
During his countdown, it takes Alan eight seconds to get from 7 seconds to 5 seconds.
The computer voice does not match what is written on the screen. The screen shows "Resources capable of sustaining human life", but the voice says "Resources to sustain human life unlimited."
After the landslide, the wind somehow manages to move several rocks which should be impossible short of there being a tornado.
Eagle 1 lands on the pad with it's port side towards to the docking tube, but later shots show the starboard side is docked.