Factual error: When the compromising pictures of the lovers in bed are shown, it's also shown that some are taken in rapid succession, with Charles noticing, covering up, charging at the camera. All this quickfire shutter action would be really too much advanced paparazzi tech for the 20s! In the same episode Miss Fisher gets her mugshot taken and it's taken with a big and clunky camera. (00:20:00)
Factual error: At the police station, as Miss Fisher hands the food basket to Jack to walk away with Dot, a wall calendar indicating the episode as taking place on August 11, Thursday. The established year is 1928, so it should be a Saturday. (00:22:30)
Factual error: At the beginning, Charles is trying to sell his airplane to Miss Fisher: he calls it a "Tiger Moth." The series is set in the 20s, and he should have simply said a "de Havilland Moth", which were the most popular recreational aircraft of the decade. The Tiger Moth though came out in 1931, making its mention an impossibility. (when we see the plane, it's a model manufactured in 1942, going by its registration number).
Answer: Louisa's watch was broken during the struggle to get away from her attacker.
Bishop73