Factual error: Barbara shoots her revolver at the guys chasing them. When she stops and gets out of the car, she opens the cylinder and we see she only has 1 round left. However, the other chambers should still have the empty casings in them instead of being empty.
Factual error: In s01e08, "Q and A", when Yelena is playing chess, we see her use the touchscreen which represents the chessboard. However, the bottom left corner is a white square when it should be a dark square. The board is orientated incorrectly, even though the board on the floor isn't.