Brooks had been knocked over the head and "dumped in an alley", yet his clothes are clean and pressed.
Neither Frank's nor Jim's beard shows any growth from the first day to the next.
When the captured robot is first shown, the crack in it's "eye" has smaller cracks radiating from it, but the second time it is shown the radiating cracks are gone.
When Jim chokes Davis to death, his hands are on the sides of Davis' neck-not over his windpipe. Also, it takes several minutes to kill someone by choking.
At the end of the film the soldiers tell Frank that their oscillator smashes the robot's "cathode ray tube" and puts them out of commission. This is pseudo-scientific gobbledygook. A cathode ray tube is essentially a television. This means that the devastating robot army operates on home entertainment electronics.
As the robot ascends the hotel stairs, an electric cord attached to the robot is visible
When the .45 pistol is fired at the robot's glass eye, the pistol makes a sound, but nothing moves on the pistol.
After being shot, the bloodstain on Frank's shoulder never grows.
As the group ascend the stairs followed by the robot, you can see the rear wall undulating, revealing it to be a tight painted canvas.
Near the beginning when Nora is wandering alone on the streets, in the foreground is a street sign warning of a 19.5% grade. At the bottom of of the sign is the ID: LA PD. Since this film was made in Los Angeles, that is reasonable.
When Frank and Nora are on the roof near the end of the movie, Frank casts a shadow with his arm against the painted background that is supposed to be the cityscape.
Although the soldier tells Frank and Nora that the sound vibration destroys the robots glass eye, the robot that traps them on the roof just falls over dead with no damage to its eye.