Old Wounds - S1-E1
Character mistake: After Mercer's speech to the entire crew he dismisses everyone except for the senior staff but everyone, including the senior staff, starts walking away as if they were dismissed as well.
Suggested correction: They were walking away, but not as if they were dismissed. The group of senior officers and Mercer are in a completely different part of the room (or possible an entirely different room). Notice the doorway where Mercer is standing. At the beginning, he's in the doorway and it has a white boarder and a 2nd set of doors. Then he's standing in front of a doorway with a blue boarder and no 2nd set of doors.
Character mistake: During the CO's meeting, the Captain made a mistake by addressing Commander Blackburn as "Lieutenant Blackburn." Even if he was demoted to Lieutenant Cmdr, you still suppose to address that rank as Commander or Lieutenant Commander. (00:04:44)
Episode #2.3 - S2-E3
Character mistake: DS Maxwell comes to Katy's house to interview her but when he introduces himself he says "DI" Maxwell.
Character mistake: The quote on the wall in Bethlem: Mens sana in corpora sano. 'Corpora' would be feminine, whereas 'sano' is masculine. So it should be Mens sana in corporE sano.
Character mistake: The X-ray shown when Ruth see Cade's body is placed in the wrong way. It should have been a mirror image. (00:57:56 - 00:59:06)