Revealing mistake: The two Elizabeths are both played by the same actress, except in the shots where both are seen together. Continuity mistakes in the second Elizabeth's death scene reveal this, such as the second Elizabeth's head position changing, and the first Elizabeth's jacket being open/closed between shots.
Audio problem: At the start of Nathan Bates' angry rant, he says 'What do you mean, another van of children got through the border?' and it has obviously been dubbed as it sounds different from his following lines. My guess is that he swore originally, and it was taken out by the producers at the last minute.