Deliberate mistake: Though by 1964 it was already suspected (and later confirmed by Mariner IV) that Mars has an atmosphere humans can't breathe and temperatures too low for humans to tolerate, Merritt and his crew are here exploring the planet sans spacesuits. This was "fudged" because space helmets A)are expensive, B)reflect cameras, and most importantly, C)obscure the actors' faces. (00:24:00)
Deliberate mistake: Amanda survives a plane crash into the ocean, hurricane winds in a life raft, then experimentation and attacks by giant microbes inside the alien probe. Yet when she and the others are rescued at the end, not one strand of hair is loose in her 1960s "beehive" hairdo. (00:49:05)
