Continuity mistake: In the scene where Branch and his father are target shooting, right before Branch confronts his father about having Longmire's wife murdered, he takes out his ear plugs. Then when his father triggers the trap machine Branch turns his head and you see an ear plug in his ear.
Continuity mistake: When Walt and Vic are driving during the day, the sun changes constantly when the shot angle changes from each character.
Revealing mistake: Vic and Walt are walking toward the crime scene in the snow, while Vic is complaining about the job. In a high angle, you can see two tracks in the snow ahead of the actors where they practiced the scene before.
Continuity mistake: Walt shows up to the first crime scene after visiting his daughter. He and Vic begin to discuss the girl. In the first shot of the girl, she is facing the camera and has her eyes closed. The very next shot of her, her head has moved and her eyes are open.
Other mistake: In the opening shot of the dead girl, there's a $1 bill next to her face. However, the picture on the $1 is not George Washington.
Continuity mistake: Vic and Walt are driving and Vic is talking about how she could be a stripper. This scene must have been filmed at two different times of the day as the sun is on Walt's side for his scene, and Vic's side for hers. Look at the shadows and sun glare in the shots.
The Cancer - S1-E4
Continuity mistake: When Walt walks up to his house, Henry is standing there with the pizza and Lizzie's note in his hand and the note is unfolded. In the next shot, Henry unfolds the note.
Dogs, Horses and Indians - S1-E9
Continuity mistake: When Walt is chasing Dullknife, they're on a two-lane road divided by a single dashed yellow line. However in some of the close up shots, it's now two yellow lines (a solid yellow line with a dashed yellow line). This is before they get to the road block.
Continuity mistake: When Walt is talking to the Denver detective, he opens the door to go inside and then the detective says they found the man who killed Walt's wife. Walt stands there, holding the door open still. When the camera angle changes, he's no longer holding the door open and goes to open the door again.
Unquiet Mind - S2-E1
Character mistake: When Walt is coming up to Mars cabin he hears a gun shot, he then re cocks his gun ejecting a live round, since he has not yet fired it. (00:20:30)
Unquiet Mind - S2-E1
Continuity mistake: During the day when Walt is following the Snowcat, he hears a gunshot and puts his backpack down to pull out his binoculars. He doesn't have anything covering his mouth, but in the next shot his scarf is covering his mouth. And in the previous shot we see both his hands, so he doesn't have one free to pull it up.
Factual error: Several times firearms registration is mentioned, but Wyoming has basically no gun laws. No registration is required, and no concealed carry permits are required.
Continuity mistake: Walt and Vic are in the compost heap digging around. Vic is without gloves while digging and when drinking the offered drink. She then resumes digging around with rubber gloves suddenly on her hands.
Death Came in Like Thunder - S2-E3
Visible crew/equipment: In the jail when Sal starts throwing around furniture you can see the camera man's arm.
Character mistake: Throughout season 3, whenever someone visits Henry in prison, the word "VISITOR" on their visitor tags is misspelled as "VISTOR."
Continuity mistake: When Branch hugs Cady, he places his right arm over her left shoulder, but in the following shot his arm is suddenly around her left arm/elbow.
Continuity mistake: When Mathias is dumping out the ashes, he is holding it with just his right hand and then grabs it with with his left hand (so both hands are on the bag). In the next shot, he's back to holding it with just the right hand and then grabs the bag with his left hand again.
Of Children and Travelers - S3-E2
Continuity mistake: After Sofia shoots the shotgun into the air, her hair switches from being over her ears to being tucked back behind her ears a few times, despite her hands being on the shotgun.
Revealing mistake: Early in the episode the dead body in the barn ever so briefly flutters his eyelids.
In the Pines - S3-E4
Visible crew/equipment: When Ferg is looking at the black notebook, you can see the hand of the stage crew holding it in front of his face. (00:08:55)
Answer: Something he made up.