Rosalie was the one who shot AndrĂ©.She certainly had a motive (she was rather fond of Oscar, after all), she was close enough to have done so, and thanks to Oscar, she had access to firearms and knew how to use them... Or maybe I just like the idea of a Badass Rosalie with a gun.
Oscar had a relationship with Ben Franklin.It's known he had a way with the ladies and he was in Paris shortly before the Revolution started. And it'd certainly explain why she turned revolutionary at the end. Could be a perfectly platonic relationship. Ok, I'll admit I'm just a fan of Franklin. Hey, better than John Adams, eh?
Louis-Joseph infected both Oscar and Marie Antoinette with tubercolosisThe mycobacteria causing tubercolosis stay usually latent, only causing the illness when the infectee's immune system grows weak enough to allow uncontrolled reproduction. And all of them had tubercolosis: while only Louis-Joseph's died of it, Oscar found out she had it during the Estates-General and after protracted visits to the sick Dauphin and her alcoholism weakened her immune system, and Marie Antoinette's was found out having it (alongside a possible uterine cancer) during the depression that followed Louis XVI's execution. They either got it from Louis-Joseph or the same source that infected him.
The regimental commander of the French Guards changed name after being sued by BernardIn Real Life, the regimental commander at the time of the Revolution was the Duke of Chatelet, while in the series it was a colonel De Vouillet. What if Bernard Chatelet sued him and somehow won to steal his name back in his Black Knight days?