Factual error: While the Leonov has a centrifugal section to simulate gravity, the ship's bridge is not part of it (evidenced by the stationary views outside its portholes). Yet in various scenes, including the one when Floyd rushes in to discuss his plan to return to Earth sooner with Tanya, gravity seems quite evident. Floyd marches across the compartment onto the raised pilot area's floor, then steps down from it, his foot landing audibly. Tanya's open jacket also hangs down normally as she moves about. Yet when Floyd demonstrates his plan using two pens, they float in mid air. (01:26:50)
Factual error: In the area with the lava Willie is put in a cage and lowered over the lava. She keeps dropping down until she is stopped what looks like a few feet above the lava. In reality she would have been incinerated by the heat.
Factual error: In the very beginning sequence, as the riders are galloping triumphantly across the mighty windswept plains of yore to capture Conan, you can see power lines in the background in one brief shot at the very left of the screen.
Factual error: According to "The Doomsday Machine", full impulse drive is one-quarter the speed of light. In the first two movies, Enterprise used thrusters as opposed to impulse drive to leave Spacedock, confirming the notion that impulse drive is far too fast to leave such a (comparatively) small structure. Styles, however, orders Excelsior to one-quarter impulse, which is 18,750 km/s. In one second, she will travel half again Earth's diameter. From the time he gives the order to the time we see Excelsior clear spacedock's doors is approximately 40 seconds. Even allowing 30 seconds to go from rest to one quarter impulse, spacedock must be 13-15 times bigger than Earth! That's some serious engineering. (00:23:45)
Suggested correction: I reckon the writers always refer to levels of "impulse power" precisely so they don't have to worry too much about particular speeds (personally I always thought of it as roughly analogous to gears on a vehicle, but your mileage may vary). They use impulse to leave dock in both Star Trek II: The Wrath of Khan and Star Trek VI: The Undiscovered Country (it's implied to be unusual in both cases, for what it's worth). If all of that contradicts an earlier episode, I think we're looking at more of a retcon situation than a mistake.
Suggested correction: The warp scale has been adjusted several times, so it is impossible to say precisely how fast this fictional technology is, and by extension, how fast impulse is.
Impulse drive speed on starships have been consistent. Although sometimes quarter impulse on a shuttle refers to quarter power and not speed. Even if the speed of quarter impulse is 10 times slower than suggested (and used in the series), spacedock would still be 1.3-1.5 times bigger than Earth, which it wasn't. "It's fictional technology" is usually only a valid correction if the technology isn't explained in-universe. However, when certain parameters regarding fictional technology are established (even if they set wide parameters such as warp speed velocities) violations or contradictions (through bad script writing or whatnot) are valid mistakes.
Factual error: The Russians use a beeping "radio direction finder" to find the partisans by detecting a bug swallowed by the Mayor's son. In closeups the "direction finder" is seen to be an impedance meter (used for measuring AC resistance) - it's labeled "X=(down arrow) x (up arrow)(omega)". X is the standard abbreviation for impedance, omega means "ohms" (the unit of impedance/resistance), so the label says "impedance is lower dial times upper dial, in ohms". There is a piece of spiral twisted wire across the terminals of the impedance meter which would be useless for radio direction finding. (01:19:15)
Factual error: When Jenny Hayden and Starman accidentally overshoot their destination and arrive in Las Vegas, Jenny discovers that her wallet is missing. She has no cash, no credit cards, and no identification whatsoever. The only money she has is a single quarter. Starman uses the quarter to hit the jackpot on a 25-cent slot machine, then uses the prize money to play the Horseshoe $500,000 slot machine, which he also wins. They then use the giant jackpot money to purchase a brand new Cadillac and drive it off the lot. Huge problem: In 1984 (and today), you could never collect a giant Las Vegas jackpot without several pieces of personal identification, for tax purposes. Likewise, you could never purchase and drive a brand new Cadillac off the lot without multiple pieces of identification and a financial disclosure statement (if paying cash).
Factual error: None of the "Colombians" speaks with a Colombian accent or uses Colombian slang.
Factual error: In the scene where the convoy is on the way to the Eldridge, the trucks used are M35 deuce and a half dating from 1949, the jeeps used are M151 mutt dating from 1959 (horizontal grills) . (00:05:55)
Factual error: The tigers used here are Indian Bengal tigers and this is set in Africa. Plus zebras can't be ridden as Sheena's able to do.
Suggested correction: The only striped animals in the movie are zebras, not tigers. A tiger did appear on some of the DVD covers, which is an error on the covers. For a fantasy movie, riding a zebra falls under artistic license. In any case, the zebra Sheena was riding was a small horse with makeup to make it appear to be a zebra.