When the Professor gives his talk to the Scientific Society he uses Piltdown man in the progression. Chimp:Java Man:Piltdown Man: Cro Magnon Man:Neanderthal Man: Modern Human. Piltdown Man was a fake fossil that was comprehensively debunked in 1953 - the same year that 'The Neanderthal Man' was released. en.wikipedia.org/wiki/Piltdown_Man.

When a saber-tooth tiger attacks George, the close-up image of the beast is a cheap stuffed animal with long teeth added in and whiskers drawn in. The image only appears for a second.

In the first bar scene when the hunter pours beer from the bottle to the glass, the beer is totally flat, no foam appears in the glass.