The lyrics to the song that Fleance sings at Macbeth's banquet for Duncan at Inverness are taken from the poem "Merciles Beautè" by Geoffrey Chaucer. In the context of the film this extraneously inserted song is itself an anachronism, as Chaucer lived in the fourteenth century and Shakespeare's "Macbeth" historically takes place in the eleventh century.
When first meeting the witches, Macbeth follows them asking further questions as to their prophecies.One shot shows him nearing the witches as they each hurry down a small set of stairs, the youngest witch flashes herself at Macbeth and we see an angle change to see her hurry down the same steps and Macbeth directly behind her in the shot. the scene changes to show Macbeth standing in the same position as when the young witch flashed herself at him.
When Macbeth dines after Banquo's death, time freezes for 5-10 seconds as Macbeth sees Banquo's ghost sitting at the table. This is achieved by the other actors freezing in place until Macbeth drops his chalice. During the time freeze, a man sitting at the table and facing the camera blinks his eyes.