In one scene, you see Duncan in a crowd holding a lighted candle. The film cuts to a close up of Duncan and he is holding an unlit candle, the next cut back to Duncan in a crowd again holding a lighted candle.
Duncan and his men renew their baptismal vows with a prayer composed by Pope Leo XIII in 1884. While this is technically an anachronism, it should be remembered that William Shakespeare's plays are themselves are full of similar anachronisms, therefore this can be seen as a stylistic tribute that Shakespeare himself might have appreciated.