The opening epigram "For Centuries, theologians, philosophers and poets have looked into the universe in search of proof of the devil. It would have sufficed to look into the depth of their souls." is likely apocryphal, as an an attribution to a Hieronymus A. Steinback in the XVII Century is not verified by any other source.
Glenda says she played her husband's records while he was out conducting, but the music she's shown listening to is solo piano, no orchestra to conduct. Also, Josefa is said to have been protected because she wore a pentagram, a five pointed star, on a necklace., but the emblem she actually wore was a six pointed Star of David, which could also be used as a talisman against evil..