Character mistake: President Kirkman calls a soldier a Corporal when she's wearing the rank of Specialist. Next, he calls a soldier Private when he is also wearing the rank of Specialist. (00:04:46)
Character mistake: The chessboard on the desk part way into the episode is set up wrong. Any chess player knows the "white on right" mantra for the white square being in the right corner of the board. In the show the entire board is off and black is in the lower right corner. (00:11:20)
Character mistake: The ‘Brit', Damien from Scotland Yard, and Emily are outside the archive facility - Damien pronounces ‘route' the American way (rowt, rather than root).
Answer: It's a recurring theme on the show. Characters come and go depending on the storyline. General Cochrane, Tyler Richmond, Abe Leonard, etc.