In Episode 1 Season 1 Amanda shoots her possessed partner in the head 2+ times which wouldn't be normal for a 1886 Derringer that only holds 2 bullets.
Amanda Fisher pulls her secondary weapon when she is being attacked in the house. The weapon was a Deringer handgun; it holds a maximum of two rounds, but she fires it a total of five times without reloading it.
During the fight in the motor home, Ash's right hand is briefly visible, even though this should be a wooden hand.
The flag outside the ValueMart is a 48-star flag, which is obvious by the 'square' array of stars in the Union (8x6) instead of the staggered Union stars of the 50 stars (6x5 [30] and 4x5 [20]).
For the fight scene with the possessed Vivien in the climax, a much younger stunt double wearing a curly wig can be seen portraying Vivien for much of the action scenes. She is more noticeable when Vivien has Kelly pinned against the cabinet and is attempting to stab her in the eye with her fingernails.
In the first scene when Ash is putting on his corset, his amputated hand switches between his left and right hand in the mirror.