Plot hole: It turns out in the climax of the episode that there are no bullets left in the gun and Miss Fisher knew it. That would mean then that she deliberately wasted minutes with Simon bleeding out on the floor when Chaim was holding them at gunpoint with an empty revolver, for no discernible purpose.
Other mistake: Miss Fisher takes a handwritten phrase in "ancient" Hebrew to one of the main characters to be translated. The writing is actually in cursive Hebrew and is properly written. While performing the translation however, the "expert" translator holds the writing upside down. He also follows the writing with his finger from left to right. Hebrew is written from right to left. (00:32:00)
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)
Continuity mistake: In her bedroom with Dot discussing the whereabouts of the soldier, Miss Fisher has her bare feet crossed and touching in the side shots, but separate in the closeups of Essie Davis. (00:15:15 - 00:16:00)
Continuity mistake: When Miss Fisher is summoned in the inspector's office, initially in front of Jack the desk is clean, just papers. In the rest of the scene, two pens make a sudden appearance. (00:26:20)
Factual error: Looking at the lending list card, we see that Saul returned the book on the 26th of August 1928, a Sunday (when we assume the privately owned store would be closed), and more importantly, that his last name changed: from Saul Michaels as he was mentioned in conversation, to Saul Abrahams as it is written on the card. (00:13:05)
Answer: Louisa's watch was broken during the struggle to get away from her attacker.
Bishop73