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: When Frank is starting to show Amy how to take the gun from him he removes the magazine and makes the statement "clip empty" - any Marine, certainly one as well trained as him would never refer to that as a "clip" - it is a magazine. A "clip" is a device intended to help rapidly load ammunition into a magazine.
Such Sweet Sorrow: Part 2 - S2-E14
Character mistake: When Tyler arrives in the Klingon ship, Captain Pike says "calvary arrived just in time." The word is "cavalry." The subtitles show "cavalry."
Character mistake: At the start of the episode when Clay is done brushing his teeth and standing in front of the mirror without a shirt, he has no tattoos. He has been seen several times with tattoos on his arms that are not even covered by a normal T-shirt. (00:05:02 - 00:05:23)
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: One of the characters, Agent L, is usually talking to the kids via some gadget with bad audio. In The Golden Gauntlet, the first time she appears on the screen she misnames Agent J, calling him "Agent G." She then later in her speech calls him by his name correctly.
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.
A Stolen Truck and Going on the Lam - S6-E16
Character mistake: Missy and Paige are stopped by a police officer "just outside Baton Rouge" But in Texas, the family is told they are outside Boca Raton.
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)