When Phryne and Aunt P. have tea at the end of the episode, and Phryne goes to cut another slice of cake for Aunt P., you can see that the cake has been pre-cut.
At time index 1:43, the factory worker who dies at the start is introduced to Phryne as Daisy Miller by Dr Mac (the one person who should know better than anyone, as it turns out). Everywhere else, including the screen credits, she is referred to as Daisy Murphy.
When Phryne, Inspector Robinson and Constable Collins rush into the factory (at 50 min), Robinson and Collins turn right while Phryne goes straight on. Collins goes right but it appears Robinson slips on the floor. This is obscured by Phryne but in one frame Robinson has one foot in the air to the left of Phryne and he isn't shown going right.