Unreal City - S2-E1
Continuity mistake: While Lieutenant Granderson is being escorted around the compound and walks to the class, she is wearing O-3 rank (two silver bars) on her collar, despite never being promoted during the show to this point. Later on in the episode, when she is talking to her mother, she is wearing O-2 rank (one silver bar) again. (00:13:35 - 00:34:15)
Continuity mistake: Chandler is reviewing the President's paperwork and finds the manifests which brought his wife and daughters from Washington (document dated 07-05-13) and his son from Detroit (document dated 08-02-13). He then checks the computer for casualty figures in Michigan where the son was originally from (dated 8/4/14-onwards). So the plague hit in early August 2014, but the documents show the family leaving their home a full year earlier. This is not a plot issue (no, they did not fly out a year prior to the plague), but rather a prop-maker error. (00:28:00)
Continuity mistake: The "real" time between the end of season 1 and the beginning of season 2 is supposed to be 1 day, but Tex's hair and beard are 2 inches longer.