Continuity mistake: When Sister Aloysius is walking Mrs. Miller to work, the Sister's umbrella handle is hooked to the left, then hooked to the right in the next shot. (01:12:10)
Continuity mistake: After speaking to Donald's mom, Sister Aloysius is standing in the wind with leaves floating in the air. The quantity of leaves situated on the ground changes between shots. (01:17:55)
Father Brendan Flynn: I can fight you.
Sister Aloysius Beauvier: You will lose.
Trivia: Philip Seymour Hoffman was the only actor who knew whether or not Father Flynn was actually guilty.