Other mistake: When Gordon and the troopers bring the unconscious Venusian ladies in and place them in the chairs, the chairs are almost in the middle of the room. When the girls come to, the backs of the chairs are right up against a wall.
Other mistake: "Night of the Bubbling Death": When West lifts the unconscious bad guy by the shoulders and prepares to drag him out of sight, you can see drag marks already in the dirt from previous takes.
Other mistake: Balya, the Turkish representative, is killed by a knife protruding through the back of his chair. But when he falls to the floor, leaving the knife behind, there's no blood on the blade.