Goofs

When Danton is being conveyed to the guillotine, Klaus Maria Brandauer's hands are tied behind his back in some shots but not in others.

The guillotined bodies were obviously human-sized props. As soon the guillotine decapitated the head, there should have been blood squirting.

Necker is depicted as being a Swiss by Louis XVI. In fact, Necker was from Geneva and this city was still independent until 1815, when it became a part of the Swiss Confederation.

The orchestra plays on modern instruments (e.g. a traverse flute made of metal)

When Marat confronts Lafayette immediately before the National Guard fires into the crowd at the Champs de Mars, a modern wristwatch is visible on the man immediately behind and to the left of Marat.

Strange enough in a very accurate movie, there is a mistake about the location of the guillotine on the place de la Concorde. When Louis XVI was executed on the 21th of January 1793 the guillotine stood exactly between the center of the square and the entrance of the Champs-Elysées. Then, a few months later, it was moved on the opposite between the center of the square and the entrance of the Tuileries garden. It was on this spot that Marie-Antoinette was guillotined so were the defeated leaders of the revolution (the Girondins, the "exagérés", the Danton group then Robespierre and co).