Revealing mistake: When Simon prepares an injection for Jayne, you can see him insert it and draw back a considerable amount of fluid from the medicine vial, but the level of liquid in the vial does not drop.
Firefly (2002)
2 revealing mistakes in Trash
Starring: Alan Tudyk, Nathan Fillion, Adam Baldwin, Morena Baccarin, Gina Torres, Summer Glau, Jewel Staite
More mistakes in Firefly
Mal: Now, you can luxuriate in a nice jail cell... But if your hand touches metal, I swear by my pretty floral bonnet I will end you.
Out of Gas - S1-E5
Trivia: Wash sets up a big red button for Mal to push to call back the shuttles if help arrives. He tells him "When your miracle gets here, just hit this button". After the show got cancelled, Alan Tudyk sent the button to Joss Whedon with the same message enclosed.
Question: In some scenes, why do the Serenity crew members speak Chinese?
Chosen answer: One of the premises of the show is that the two major Earth societies that survived, and ultimately merged, were the Chinese and Americans. As a result the common language includes much Chinese. Clothing, signage, and building designs also have a heavy Chinese influence.