The saber-toothed tiger's long fangs aren't shown as it's walking around, but does show when he jumps on a car and in other scenes.
The sabre-toothed cat's "tusks" only show up on the cat's body after its killed. All the shots earlier are of an ordinary tiger with normal fangs.
In discussing the development of the brains of the most primitive man to modern man, Professor Groves rates Neanderthals as higher on the evolutionary chain than Cro-Magnon man.
Sabre-Toothed cats (not actually related tigers) only died out around 10,000 years ago, not over 1 million years ago as stated by Dr. Harkness.
The first time the Professor turns into The Neanderthal Man, who goes over and opens a window to leave and closes it when he returns. How would a neanderthal man know how to open and close a window?
When the transformed Professor Groves attacks Buck and Nola at their picnic, the stunt man's hands are not made up as the Neanderthal Man first appears. Then his hands alternate between hairy-and-long-nailed and normal from one shot to the next.
In a scene where Beverly Garland is on a modeling shoot with a photographer, she goes behind some bushes to change into a bathing suit for the shoot. The actress who emerges in the swimsuit is obviously another actress, not Beverly Garland.
Dr. Groves is the author of a book titled *The Evolution of Early Man in North America*. Even in the 1950s it was widely accepted that humans did not evolve in the Western Hemisphere. If the scriptwriters were ignorant of this, then it would be a factual error; if the scriptwriters knew and invented the title to show the crackpot mentality of Dr. Groves, it would be a character error.
In several shots of the tiger walking around, a leash guiding the animal is visible.