Other mistake: Episode 13-12: "Shadow (2)." When Cruger is challenged to defeat 100 robots, a red countdown meter appears on the screen, ticking down each time Cruger dispatches an opponent. When the counter is at 21, Cruger slices his sword at a robot, which then goes down. But the counter stays at 21 and only goes to 22 when he slices at the next robot. Every robot in the sequence goes down after a single hit from Cruger's sword.
Other mistake: Jack follows J. Edison Nash to a wine warehouse and watches as Nash punches numbers on a keypad in order to gain entrance to a private room. Nash punches the 6 and a beep is heard. He then punches the 8 and another beep is heard. During a close-up of Jack, four more beeps are heard, for a total of six. Jack says the number out loud - 862, which is only three digits.
Other mistake: Throughout the episode, including the very first shot, we see the sun is shining brighter and hotter than usual. This lends credibility to the theory that Superman's powers are responsible for increased solar activity. Later on in the episode it is revealed that the heatwave is being orchestrated by Lex Luthor, who is is heating an underground river to coincide with Superman using his powers. Lex does not however have any control of the weather, and no explanation is offered for why the weather conveniently 'played along' with his plan.
Other mistake: When Frasier enters the apartment, Martin and Sherry are talking in the kitchen. If you listen carefully to what they're saying, their conversation makes no sense. Martin says something along the lines of "Daphne is really a very nice girl" before suddenly, in a very different tone of voice, he says "You're right, we're not getting enough privacy around here". Seems like a big chunk of conversation was edited out.
Other mistake: Dr. Mike spots a charred Bible within the charred piles of books, and heads into the church. The Reverend is giving a sermon on morality, and offers Dr. Mike the floor and she briefs about certain stories in the book, which would be considered scandalous, without mentioning the book's title, then hands it to the Reverend who agrees such stories are scandalous, until he turns it over, to see that its 'The Holy Bible'. Being a Reverend, he should know The Bible cover to cover, but reacts surprised or shocked over the mentioning of the scandalous stories. (00:36:00 - 00:41:00)
Other mistake: When Butt-head is purchasing the pork rinds from the vending machine, he notes that the selection for them is F2. When he is pressing the buttons to dispense them, he presses the F button twice, but never the 2 button. Somehow, the machine still dispenses the correct item.