Other mistake: Superman is always seen with his arms extended when he flies, but when he lands, it's always feet first. He's never seen changing his position to account for this.
Continuity mistake: Often the show reuses footage of Clark Kent changing into Superman, but the footage has him removing his hat, even though before he rushes off to change he is usually not wearing a hat.
Audio problem: During the opening credits no one moves their mouth when they notice Superman and say "it's a bird...it's a plane..."
Continuity mistake: At the beginning when the lady at check in is passed out on the floor, she is right up against the desk, but when Lois goes behind to tend to her, she is further away from the desk, and closer to the wall.
Continuity mistake: The mirror that the gentleman looks at to see if he is being attacked from behind changes completely when in a close-up, from a circular mirror to a more triangular one. (00:04:34)
Crime Wave - S1-E24
Other mistake: Whenever a newspaper is shown, the content is the same no matter what the headline is.
Visible crew/equipment: Lois and Clark are in the car when Clark finds a bomb in the backseat. He throws himself and the bomb from the car, and it explodes. When Lois stops the car to see if he is okay, virtually the entire crew is reflected in the side of the car - the camera operator, the man with the boom mike, and several others. (00:12:15)
Other mistake: When Superman pulls off the vault door and places it flat against the wall, it begins to fall back and he holds it back. He then leaves and the door is suddenly propped against the wall.
A Ghost for Scotland Yard - S2-E8
Factual error: Bearing in mind the episode takes place in London, Sir Arthur MacCready is driving his Rolls Royce. The car has the steering wheel on the left hand side. A true British Rolls Royce would have the steering wheel on the right side. This is a Hollywood Rolls Royce.
A Ghost for Scotland Yard - S2-E8
Visible crew/equipment: Superman takes a running leap to get himself airborne. For a split second the viewer can see the springboard he jumps from.
The Dog Who Knew Superman - S2-E9
Other mistake: A gangster pushes a dog into a well and the dog can be heard splashing around. The man's wife is furious and several people are unable to retrieve the dog. Superman tunnels into the ground and into the bottom of the well and emerges holding the dog. Both he and the dog are completely dry.
Revealing mistake: When Superman is looking down at the earth, the cloth the model is sitting on is evident in the bottom right corner. (00:22:40)
Jimmy Olsen, Boy Editor - S2-E22
Continuity mistake: In the first episode, "Superman on Earth" (and one subsequent episode) Jimmy introduces himself to Clark as James Bartholomew Olson. In the episode "Jimmy Olson, Boy Editor" the sign on the Editor In Chief's office door reads James J. Olson.
Revealing mistake: When the robot releases the balloon with the bomb attached, the wires used to pull the balloon up are visible as the balloon rises through the skylight.