When de Villefort during the 100 days reign of Napoleon starts writing a letter to release Dantès, he stops to show his visitors to the door. When he returns to his desk and puts the letter into the drawer of his desk, the letter is already finished and signed.
When Dantès jumps into the water on the island Monto Cristo, which is supposed to be uninhabited, two houses can be seen in the distance behind the tree line.