Continuity mistake: When Myka pulls up to the warehouse for the first time, Lattimer's car is nowhere near where she parks, and it can't be seen when they are talking for a moment. When the door opens, however, we see both cars fairly close to each other, but if they really were that close, Lattimer's car would have been visible in the previous shots.
Factual error: In the banner for the exibition in France at the start, the French isn't right. It says "Opéra nationale" and "La morte de Marie Antoinette Des objets fabriqués de le temps de Marie Antoinette". It should be "Opera national" and "La mort de Marie Antoinette Des objets fabriqués à l'époque de Marie Antoinette" or "des objets fabriqués du temps de Marie Antoinette".
Continuity mistake: When Myka and Jinks first see the trumpet player, the camera stays on him while he plays. At one point he plays a long tone and the camera shows him press the first two valves as if to change a note. The note he is playing continues uninterrupted however. While there are some notes that can be played with more than one fingering, changing valves in the middle of the note always produces a momentary interruption of the note, at the very least.
Factual error: The bank robbery scene is supposed to take place in downtown Chicago, but streetcar tracks can be seen on the road outside the bank, and a street sign for York Street can be seen at an intersection. Chicago has neither streetcars nor a York Street. (The scene was filmed in Toronto.).
Other mistake: Charlotte enters the Duchess' bedroom, walks past Pete & Myka, with her hand behind her back, hiding something. She stands in front of them, trained security people; neither of them notice the gun in her hand (which is visible to the camera, so it is not hidden via artifact), before she shoots her husband.