When Seth is firing his 6 shot revolver at Ranger Freddie he fires 5 shots but two unfired rounds can still be seen through the front of the cylinder.
(at around 29 mins) Seth Gecko is waving around his already cocked revolver (a Ruger Super Redhawk Alaskan) when a cutaway shot shows him cocking the gun again.
Seth and Richie's car has a Kansas license plate on the front. In Kansas, license plates are only placed on the rear of the car.
The ranger mentions that Texas penal code 46.02 requires weapons to be registered. This is not true.