Other mistake: At the end of episode 2, Robin escapes from the Visitors into the wilderness. In episode 3, she's seen in an internment camp with no explanation as to how she got there. She is also wearing different clothes. She later escapes the camp along with other resistance members. Then at the beginning of episode 4, she is back alone in the wilderness, wearing the same clothes as at the end of episode 2. My guess is that episode 3 was added as an afterthought.