Factual error: The snub nosed revolver used by Miss Fisher, a J-Frame S&W, was not produced until 1950.
Factual error: There is no way Laurel Lance would have been allowed on the prosecution team for Moira Queen's murder trial. Due to the facts that she both dated and as a lawyer represented the defendant's son, the defendant's daughter used to intern for her, and her boyfriend was one of the people killed in the Glades, it would have taken all of two seconds for the court to have her removed if she didn't willingly recuse herself, since her presence would be a major conflict of interest.
Factual error: Noticed this watching season 2, and I assume it was also the case in season 1. The entrance of the Miramar Playa has flags from various countries flying. One of them is the Canadian flag with the maple leaf. Wrong flag. In that period the Canadian flag was the "Red Ensign", or "Dominion Flag." The maple leaf flag wasn't introduced until 1965.
Factual error: Chief Superintendent Hilton wears the ribbons of the General Service Medal (awarded for military service in a combat zone, most commonly in Northern Ireland) and the Police Long Service and Good Conduct Medal (awarded for twenty years' service), but not the Golden Jubilee Medal (awarded to all officers with five years' service in 2002), which he would also have. When he reappears in Series 4, he is wearing the Golden Jubilee Medal, Diamond Jubilee Medal (awarded in 2012) and Police Long Service and Good Conduct Medal, which would all be correct, but no longer has the General Service Medal.
Factual error: A plastic bag of items is found under the footboard. Plastic bags weren't invented in 1969. They first appeared in public in 1979.
One Watson, One Holmes - S3-E19
Factual error: In the scene in the hospital, the guy who drove his motorbike into a van has an IV canula in his right hand, but the IV pole and the IV bag are on the left side of the bed, which means the IV line has to be long enough to go up to the bedhead, then behind the bedhead and then up to the bag, leaving no way to check for air bubbles.
Factual error: When Susan is sorting Ruth's things, she finds Gordon's iPhone wrapped in a newspaper from 1994 with her voice-mail to him and realizes he went back in time, where Ruth killed him and took the phone from his corpse. Even if the phone had been turned off, after 16 years idle, the battery would have died long ago, but we see the phone is on with her message waiting. (00:55:50 - 00:56:45)