The lighting and weather in the film can seemingly change from shot to shot in many scenes. However, this is a low budget film where the director did not have the luxury to wait around for conditions to change, especially at the location chosen for this film.
It is obvious in some shots of the dogs that some sort of prosthetic or other means is used on them to keep their "snarling" expressions going, as they do not change in the least at certain points in the film.
When Jerry gets into his truck to go after Walker, who has gone down to the pier after hearing a power boat, a reflection of a large square studio light is visible in the window of the truck's driver side door.