In one scene, Remington tells Patterson that "We have an expression in prize fighting: 'Everyone has a plan until they've been hit.' Well my friend, you've just been hit." The events of this film take place in or closely around 1898, however the prizefighting expression used by Remington was coined by World War 2 era boxing great Joe Louis, who was not even born until 1914.
When Robert Beaumont asks Col. Patterson to build the bridge, the world map behind him shows countries like India, Pakistan, Sri Lanka and various African countries which were obviously not separate countries in 1896.
When Patterson is waiting up on his perch (with the baboon as bait), the familiar "Who-cooks-for-you" call of a barred owl (Strix varia), only found in North America, can be plainly heard in the background. Although there is a species known as the African barred owl, it is an entirely different species (Glaucidium capense) and is much smaller, with a call bearing no resemblance to that of the larger American species.
During the camping scene with Patterson, Remington, and Samuel when they are celebrating the killing of the lion, the two prominent constellations in the night sky are Ursa Major and Orion. These constellations are not side-by-side and Orion does not show in the southern hemisphere during the winter season anyway.