Character mistake: Kitty wants to reunite Bob and Midge together, saying it will reunite their only daughter. Bob has 3 daughters (just seen the younger one once). (00:12:30)
Let's Spend the Night Together - S7-E2
Factual error: After Kelso gets the call that his girlfriend's water had broken and runs out of the room, Fez answers the phone. In the background there are several license plates on the wall, one of which is an Indiana "Amber Waves of Grain" design, which was first issued in 1993.
Mother's Little Helper - S7-E7
Continuity mistake: When Kitty is showing Red "The Joy Of Sex" in the kitchen, the book goes from open to shut instantly between shots.
Character mistake: When Bob shows up in the driveway with the free calendar from Red's muffler shop, the calendar says "Foreman and Son." Their last name is spelled "Forman" without the E.
Continuity mistake: In the crowd scenes, Jackie comes back to her seat. A man sitting next to Donna looks at Jackie. The scene changes angles, and the man is looking straight.
Continuity mistake: When Donna introduces Sarah to the gang, she states that it took her 6 months of sorting records to become 'Hot Donna'. In season 3 episode 14 "Radio Daze" Donna has just started working there and gets the name 'Hot Donna' immediately. (00:01:20)
Factual error: Sizzling Sara is doing her live radio broadcast in front of a rack of magazines. One of the magazines is a Robin comic book. The series of Robin comics that used that logo began in 1993, 14 years after the episode takes place. (00:15:35)
Oh, Baby We Got a Good Thing Goin' - S7-E18
Continuity mistake: When Kelso is trying to get the baby to not cry, you can tell Bob covers its face to the camera so we don't see that it's not actually crying. Cut to a different angle, and the blanket surrounding the baby has moved. Cut back, and the blanket is covering the baby again.
Answer: It's Ashton Kutcher's dog.