Factual error: A map of Canada appears behind the guys as they're being questioned by the Mounties. The territory of Nunavut, which was not officially drawn until the year 2000, appears on the map. It definitely did not exist in 1978. (00:18:45)
Continuity mistake: Aston Kutcher slides out behind the car and screams in excitement while blowing an air horn. When he does, the wind messes up the front of his hair. A few shots later, it's neatly combed again.
Continuity mistake: Hyde must have gone into the future to get his Spiderman pillowcase because it has the Spiderman logo from the 1990's on it, not the 1970's one.
Continuity mistake: Jackie enters the basement and say: "Oh my God Donna, great story." while she is holding the newspaper by the sides. In the next shot, while the gang is laughing, she is now holding it by the bottom.
Factual error: Eric compares Jackie and Kelso's breakup dilemma to "Sophie's Choice...but for morons." Sophie's Choice was not published until 1979 (the movie in 1982), when this episode takes place in 1978. (02:49:00)
Factual error: Eric makes a reference to "Sophie's Choice." This episode is set in 1978, but the book "Sophie's Choice" wasn't published until 1979, and the film adaptation wasn't released until 1982.
Continuity mistake: When Kitty asks Red for a cat Red is reading a copy of Time magazine. He closes the magazine and puts it down on his knee while he tells her why he doesn't want a cat in the house but in the next shot the magazine is back in his hands and open to where it was before he closed it.
Continuity mistake: The unibrow drawn on Jackie changes between the time we first and last see it. It's thicker the second time.
Everybody Loves Casey - S4-E26
Factual error: The gang keeps referring to the theme park 'Great America' as "Six Flags." Up until the 80's the park was actually Marriott's Great America. There is no other Six Flags theme park in the area. - from Wikipedia "Marriott Corporation began construction on the park in 1974, and opened it in 1976 as "Marriott's Great America". In 1984, the park was purchased by Six Flags Corporation, becoming the 7th Six Flags park."
Revealing mistake: The scene where Donna and Eric are running towards each other, each shot of Donna and Eric individually shows them running past the same umbrella and surfboard. They were using the same section of the beach to shoot both Eric and Donna running.
Over the Hills and Far Away - S5-E6
Continuity mistake: When the girls go to Marquette the signs say 'GO GOLDEN EAGLES', however before the mid-1990's Marquette's nickname was 'the Warriors'.
Visible crew/equipment: As Donna plays footsie with Eric in the car while driving up to Jackie's ski lodge, a crew member's arm can be seen in the backseat. (00:05:17)
Continuity mistake: When Red and Eric were talking in the driveway there was a van right next to them. The tail lights shown on that particular model were only produced in the mid 80's and later.
Factual error: Kelso is wearing a t-shirt with Dirty Harry on it saying "Go Ahead, Make My Day". Sudden Impact was the first Dirty Harry movie to use that expression and that film didn't come out until 1983.
Continuity mistake: At the end of the episode "You Shook Me", Jackie is talking to a drunk Kitty who is putting mini umbrellas in Jackie's hair. The first shot of her doing this, she puts a green umbrella on the right side of Jackie's head. After Kitty asks for more umbrellas, the shot changes to Jackie which now has a pinkish, red umbrella on the right side and two green ones on the top.
Character mistake: As the little boys are trying to get a peek at Donna's breasts, you see more and more of them. The first two times, you can't see them. The final time, you can see a kid or two far left. They're having trouble standing still. When it cuts to a wider shot, the kids come from behind the wall to see Donna. Chances are, since the aspect ratio was intended for 4:3 TVs, they didn't intend for the kids to be visible.
Continuity mistake: When Eric and Hyde are speaking while sitting on the couch, Eric's left leg is either over his right leg or under it, depending on the camera angle.
We're Not Gonna Take It - S6-E6
Visible crew/equipment: The edge of the camera lens is visible throughout this episode. It's also known as vignetting.
We're Not Gonna Take It - S6-E6
Continuity mistake: When Eric is carrying the tray and they're trying to get him to drop it, he hops over a chair. The tray rotates between cuts. Look at the glasses.
Revealing mistake: When Fez and Suzy first meet, they do "12345 you owe me a coke" you can see Kelso mouthing the same line as well. (00:08:04)
Chosen answer: He isn't. Time moves slowly in the show because they didn't want it to turn into "That '80's Show". In the first episode, he say's he's 17 but the second episode was his 17th birthday so he must have been 16. The first 12 episodes are set in 1976, the next 2 seasons are set in 1977, the next 3 seasons are set in 1978, and the remaining shows take place in 1979 with the final show on Dec 31, 1979 when Eric must be 20 as he turned 17 in 1976.
Myridon