Plot hole: In "I Robot, You Jane", how exactly does Willow scan Moloch out of his book when the scan is only about two thirds the width of it? (00:04:25)
Continuity mistake: Buffy's birthdate starts at 1979. In "I Robot, You Jane", when the demon pulls up Buffy's file in the school system, it shows her year of birth as 1980 and her year as sophomore. But when her file comes up on the student's computer screen, it's changed to 1979 and that she is a senior. It wasn't until towards the end of season 1 in "Nightmares" that her birth year is 1981 (on her tombstone before she comes out as a vampire). (00:08:30)
Other mistake: Willow's computer beeps twice when her first email from Malcolm is received through before she is kidnapped by Fritz, but only beeps once when the second email is received.
Factual error: When Willow is chatting with "Malcolm," she says she has to sign off the chat program after she gets nervous. However, all she does to "sign off" of the chat program is turn off the computer monitor. This would do literally nothing. The program would still be running if you turned the monitor back on. Yet the episode treats it like she's just turned the entire computer off by turning off the monitor.
Continuity mistake: In the beginning, after the monk traps Moloch and closes the book, the positions of his hands gripping the sides of the book changes slightly between cuts. (Ex. His left hand is lower, then suddenly slightly higher between edits).
Deliberate mistake: When Willow goes into her dark bedroom, she turns on her lamp. Somehow, her tiny lamp illuminates the entire room and also casts a shadow behind her, even though it's behind her. Clearly, when she turns on the lamp, they also turned on some set-lights in front of her to make the room bright enough for filming. There's also something else that gives it away-when she turns on the lamp, the studio lights come on a split-second later - just enough that if you look closely, you'll notice the delay.
Deliberate mistake: When Buffy, Xander and Giles try to "delete" Moloch from the computer, watch the computer screen as she sits down. There's already a folder labeled "Willow" on the desktop. Buffy then types in the word "Willow" to search for the document (without clicking on any sort of search bar, so typing it would do nothing), then says something along the lines of "That's probably it" and proceeds to click on the "Willow" folder... that was already on the desktop. The entire scene makes no sense.
Continuity mistake: When Buffy and Willow arrive at school at the start of the episode, Willow is wearing very dark, completely opaque tights that look to be black or at best very dark navy blue. When Xander finds her in the next scene, which takes shortly after on the same day, she's suddenly wearing much brighter purple tights.
Continuity mistake: In the beginning of the episode, when Willow gets the email from "Malcolm" and says "He's so sweet! What should I write back?", she instantly goes from facing forward at the computer to facing sideways at Buffy between cuts.
Chosen answer: He had larangitis and because of the shooting specifications they had to have him shoot the scene with a bad throat, they then re-recorded his lines and dubbed them. At various points during the scene and indeed the episode you can see him touch his throat or rub it.