The gorgonopsids have scaleless, mammal-like skin, but when a mummified gorgonopsid is shown, it has reptile-like scales.
The narrator claims that nothing will live to rival the Gorgonopsids in size until the giant dinosaurs evolve, but this is not true, since other, similar-sized animals (such as the animals traditionally grouped under "Rauisuchia") have existed after the Gorgonopsids went extinct but before the large dinosaurs evolved.
In the American version, the narrator says some bogus things. He says that the Scutosaurus digested plants with the help of small stones called "gastropods" - the correct word is "gastrolith". Gastropod is the scientific name of snails and slugs. He also says that Euparkeria will evolve into dinosaurs such as Brontosaurus. While Brontosaurus is nowadays considered a distinct and valid dinosaur genus by some scientists, at the time this show was made it has been seen as invalid (the original British narration says Diplodocus instead, which is undoubtedly a valid dinosaur name).
When one of the gorgonopsids hops into the water-hole, creating a muddy splash, there is a bit of earth protruding the surface of the water. Just as the splash occurs, it simply disappears and is replaced by a brownish silhouette that bears its shape, though it's missing the patterns and details that the bit of earth originally had. It is as though the animator working on the shot had simply forgotten to add it on top of the splash-effect.
As the Lystrosaurus herd marches into the river, many of the animals don't have reflections on the surface.
When the Gorgonopsid kills the Scutosaurus, it doesn't cast a shadow on it.
When the Scutosaurus dies, its front leg briefly clips into the ground, and its wrist is also unrealistically twisted, distorting the CGI model.
When the Labyrinthodont attacks the Gorgonopsid, and the latter pushes up some sand with its left foot, the sand overlaps the Labyrinthodont, even though it should be behind it.