John Robinson states that he is at 10,000 feet above the planet, but the corresponding shot shows that he is still in outer space many miles above the planet.
Prior to the landing on Preplanis, as Maureen descends the ladder to the lower deck and then prepares to strap herself in, a repeating electronic sound can be heard. This was the radio signal received from the alien spacecraft from The Derelict (1965) which John had remarked that he'd "never heard a [sound] like it before."
The giant electric tumbleweed sheds light only during closeups of the spacefarers; in the long shots, there are no reflective effects whatever, not even on the glass panels of the chariot.
The reason for Major West riding down the crash landing in a freezing tube was to reuse stock footage from the unaired pilot. This created a continuity error because in the pilot there were only a few flashing light displays near the view port. For the series, many more displays (including a radar screen) and controls were added. These appear before the crash landing, disappear during it, and reappear after it.
When Smith and the Robot are playing chess, the Robot's left pincer has a straight section with a wide end, allowing the actor in the suit, Bob May, to manipulate the chess pieces. A few minutes later, when the Robot exits the elevator, the extended section of the pincer is gone.
While Will and Smith are listening to the interchange while discussing the Robot's ability to play chess, West says Robinson's altitude is 40,000 feet. Twenty-four seconds later, West announces Robinson's altitude is 10,000 feet. This means that Robinson is travelling at more than 850 mph vertically with an unknown horizontal vector. Not only would he be incinerated at that point, he would have hit the surface within 8 seconds.
While in the pit John Robinson reaches for the radio and it explodes. A few scenes later as John Robinson is climbing out the radio is visible once again!!.
When West and the family take off in the Chariot to go look for John, the tracks in the sand start when the Chariot moves. Since it had to be assembled and parked by the hatch, where are the tracks from wherever it was unloaded from the ship to that point?
Dr. Smith blinked several times while in the freezing tube before the robot revived him.
During the time John Robinson is falling toward the planet, cable(s) attached to him can be seen at times.
When Will is fixing the chariot towards the end of the episode a crewmember's face is visible in the glass of the chariot.
As the Robot first exits the spacecraft to analyze the soil and atmosphere of Preplanis, he bumps two rocks, causing them to roll away. After having come to a complete rest, the rock on the right moves again, obviously getting pulled across the soil by an off-camera stagehand.
Just before the soil probe emerges, one can see a tow cable attached to the rear of the robot at ground level.
After the encounter with the giant electric tumbleweed leaves the chariot disabled, John orders everyone to abandon the vehicle to walk back to the spaceship. Maureen says "Everybody out. Pick up your parkas." But, there are no parkas to pick up; everyone is already wearing their parka, and no one is carrying any clothing of any kind as they climb out.
Dr. Smith calls his fear of heights "batophobia". The usual word for fear of heights is "acrophobia". There is a similar term that sounds like what Smith said, "barophobia," which means fear of gravity.