Factual error: When Miss Fisher takes the teacup from Hugh to bring it to the housekeeper, she passes by the calendar. It shows December 17 as being a Saturday, not consistent with the year of the show. (00:30:55)
Factual error: When Mr. Butler takes the hashish-laced cake, "It Don't Mean a Thing (If It Ain't Got That Swing) " is playing, composed in 1931, later than the 1928 setting.
Answer: Louisa's watch was broken during the struggle to get away from her attacker.
Bishop73