Revealing mistake: When the band in the nightclub performs the made up song "Mr. Music Man", the suave Mr. Stone, the musician Miss Fisher ends up dancing with, is doing one heck of an hilariously incompetent job at faking to play an instrument, basically playing air-banjo strumming about 3 inches above where the chords are, and wildly off tempo. In the closing bit of the song (as the singer sings "To sin") he even moves his hand at the side of the strings and not above them. (00:03:30)
Ruddy Gore - S1-E6
Revealing mistake: It is revealed that the ghost apparitions come through thanks to projection over falling sand, but that's not the trick used in the actual movie shoot: no sand is falling and accumulating on the floor in the last ghost apparition (when we can see the floor for a while) and in the second apparition (to Miss Fisher backstage) the line of sand was in the wrong direction for it to act as screen.
Death at Victoria Dock - S1-E4
Revealing mistake: When Miss Fisher reads the newspaper just before the final reveal, it's Friday 26 August 1928's newspaper. Remarkable, considering 6/26/1928 was a Sunday. It's not the only peculiar trait of that first page though, as in the text you can read the name "Casey Anthony" multiple times together with "not guilty" in bold text etc., all parts of a tragic story happening over 80 years after this episode. (00:52:35)
Revealing mistake: Jack lights up a match to see better in the darkness of his prison with Jane. As Jane gasps, the match is extinguished, but the additional light in the room remains the same. (00:41:50)
Revealing mistake: The leap between two buildings during the rooftop chase is just awkward looking. No way the simple little hop filmed from behind can bring the man over the long distance shown in the following shot. (00:14:40)
Death at Victoria Dock - S1-E4
Revealing mistake: At the end of the episode, Miss Fisher talks to Mr. Waddington about her compensation of choice in front of a matte paint of the background. (00:54:20)
Answer: Louisa's watch was broken during the struggle to get away from her attacker.
Bishop73