One of the Corsicans in the inn states "Our fatherland is Italy with the Duke of Savoy". The Duchy of Savoy had ceased to exist in 1713 (eighty years earlier), when the Duchy acquired the Kingdom of Sardinia and the Duke then bore the title of the King of Sardinia. Italy was a geographic place not a political entity at this time.
Flags of the British troops at the battle of Toulon show either the Union Jack or a regimental colour with the Union jack in the upper left canton. However the Union Jack used is the one adopted in 1801 and incorporates the red cross of St Patrick, whereas the Battle of Toulon was in 1793. Similarly the ensign flown by the ship that sees Napoleon at sea after fleeing Corsica is the white ensign of the White Squadron of the Royal Navy, but it too uses the 1801 Union Jack pattern
The French troops attacking Toulon and the Army of Italy use flags with triangles in corners, the pattern introduced in 1804. In 1793, the pattern was based around a large central cross with the regimental number surrounded by a wreath, with different patterns and colours in the four corners (one flag similar to this is seen carried by the Army of Italy).
Around the tine that Danton is delivered to the Executioner, there are several scenes with Robespierre seated at the desk. The position of his eyeglasses varies between being on his head, on the desk or in his hands.
In Act IV - the Army of Italy sequence - there are a couple of shots of Napoleon's head where the image has been flipped. This is obvious because usually when viewed from the front, the tricolor on Napoleon's hat is over his left eye (the viewer's right), whereas in the flipped clips it's over his right eye (the viewer's left).
Junoit makes a comment about not needing sand when an artillery shell dumps soil on the sign he is painting. This is based on an actual incident, but Junot was writing a letter for Napoleon not painting a sign.
One of the Corsican insurgents says "Our fatherland is Spain with Buttafuaco! Death to Napoleon Bonaparte!" The name is misspelled. The person referred to is Matteo Buttafuoco, plenipotentiary of the independent Corsica sent by Paoli to treat with France.
In the last sections of the film, when three images are combined to across the screen, some of Gance's technical limitations can be noted. In shots of the Army of Italy that one of the images is duplicated and reversed to give an illusion of more soldiers. Shots of Napoleon show differences in the position of the cockade on his hat - sometimes over his left eye and other times over his right - showing that some of the images have been similarly reversed.