Treat Williams is repeatedly shot in the chest and back by the zombie thugs, resulting in many bloody wounds. In the next scene he's shirtless and there are no bullet holes in his body.
When Roger is examined by Rebecca after his resurrection, he cuts himself and does not bleed as he is found to have no pulse. Later he is shot and bleeds from his wounds, which contradicts his earlier examination.
Roger copies down the number found inside the lampshade at Loudermilk's crypt. This number is 2639362867. He later deduces that this number was used as code to spell out "BODYDOC", Dr. McNab's license plate. While the first 7 numbers could spell that out, what about the last 3 numbers at the end? All 10 together could spell out "BodyDoctor", leading to the deduction of the plate number.
When Mortis is attacked with the meat cleaver, his hand is cut between two fingers leaving the two sides split apart by the gash. The resulting gap makes it look like he had an extra finger lopped off, but that's not the case. In a later scene, his hand is shown being sewn up, closing the gap.
When Bigelow throws the zombie chicken into the grinder in the Chinese restaurant, it is clearly visible that he misses. In the very next shot the chicken is in the grinder.
In the first scene where we see our two stars driving in the car, the camera crew is clearly (though quickly) visible in the reflection of multiple store windows and the side of a nearby van.