When the women are lined up by their 'Madam' for Jackson Boomer (Busey) to make choice, from his POV, the focused on 'buxom' blonde choice is shown with her arms at her sides with her (dressing) shift still around here wrists; next shot - now from now their right side lined up - her shift is gone with her hands now clasped in front of her.
When Guerrero talks to his mother in the kitchen, the shots of her show their breaths condensing, but the shots of him (mostly) do not show his breath condensing.
The distinctive red plastic shotgun shell seen falling in the saloon gunfight was not introduced until 1960. This movie was set in the late 1890s.
The first topless hooker on screen appears to have breast implants about 80 years before they existed.