At the beginning of the film, Pancho Villa makes a remark about Charlie Chaplin. This scene takes place sometime between the end of 1913 and the beginning of 1914. Chaplin made his screen debut in January 1914. In any case, there's no chance that Pancho Villa would have known Chaplin's films, considering that at that time (1914) the future star was just only another Keystone employee.
The screen title "May 9, 1914 - New York City" appears over a shot of Times Square. A billboard reads "The Broadway Melody - Metro Goldwyn Mayer". That studio was founded in 1924, and that movie was released in 1929.
In the battle of Torreon, after Villa's troops retreat, and the Federales stand down, one of the scenes has obviously flipped (reversed) film. The Mauser rifle that the soldier is staring down is shown from the right side, but it is in fact the left side of the weapon.
During the battle of Torreon scene, night falls and we see a moon that is half full (1st quarter). The date is given as 30 March 1914, but on that date, the moon was a crescent and would not be half full until several days later on 4 April 1914.
Griffith is shown to be making a short western in New York in 1914. It is a very cloudy and overcast day. In reality, Griffith has already moved his stock company out to California by then, plus he would have known not to shoot on such a cloudy day (there would not be enough light for the exposure). He also did not film any westerns in 1914, and would have been at work on The Battle of the Sexes at this time.