The events in the film take place in the summertime according to Boris' makeshift headstone, but the two young ladies that encounter the fake cows are dressed in winter clothing, are talking about a ski instructor, and have skis on the roof of the car, implying it takes place during winter.
Toward the end, when the saw is turned on during the fight, the object on the "conveyor" would not index toward the saw. That is a "skatewheel" conveyor, it just has a series of rollers that only allow a person to easily push something down the line. There are no motors, belts, etc. to automatically drive or feed anything down the line to the saw.
The dis-articulated torsos Vincent hangs upside down on hooks are anatomically incorrect. The crotch between the leg stumps lacks both genitalia and any wounds suggesting their removal. The way Vincent pushes the torsos down the line appears to be an attempt to disguise this.