The arrival of the spaceship knocks out the electricity supply to the telephone and the car ignition. However, it does not affect the domestic supply to the hotel since the captives try to electrocute Nyah by wiring up the door handle.
When Mr. Jamieson hands Carter the revolver it is a small one of the "top-break" style with a very short barrel. Yet when Carter points the gun at the Devil Girl and fires, it has transformed into a larger, longer-barreled, revolver of the "swing-out cylinder" type.
When the "indestructable" robot Chanti leaves the spaceship, a close-up of his feet reveals paint scraping off where the joints of the suit and the boots meet.