Revealing mistake: In an imagination sequence Reese and Malcolm are throwing around Jamie, but you can see it is a doll.
Character mistake: When Otto tells Francis he has to put a horse down, Francis objects saying he's never killed anything bigger than a poodle, and that was an accident. However, in season 4 (episode 11), Francis accidentally killed Otto's pet cow. (00:11:30)
Continuity mistake: After Stevie becomes catatonic, a wrapper from a chocolate bar lands on his face, covering his glasses. The shot cuts and it's on his shoulder and then cuts again and it's on his face again.
Continuity mistake: When Malcolm is throwing the dodgeballs at Stevie, the number of balls in the bag changes between shots.
Audio problem: You can hear the new boss speak, but her mouth doesn't move. (00:16:30)
Revealing mistake: When Lois confronts Susan about not telling her about Susan's kidney disease, Susan is telling Jamie how cute he looks in his sailor outfit. When the camera is moved to a different angle, it becomes very obvious that "Jamie" is just a prop baby doll. (00:11:10)
Continuity mistake: When Susan arrives Hal is holding Jaime, and the baby's entire body changes position between shots repeatedly - in some shots the front of Jaime's body faces Hal, yet in others Jaime's back faces Hal.
Experiment - S5-E18
Revealing mistake: In the first scene, Lois is feeding Jamie while talking to Dewey. In the next clip, it changes to just a prop baby doll toy with a beanie covering a majority of his face. (00:04:25)
Visible crew/equipment: When Hal is walking the stroller with Jamie inside at the park and Hal approaches the Body Builders, the full body of a camera-man and the camera he's filming with is ridiculously visible on the right side of the screen in a wide-shot.
Pearl Harbor - S6-E4
Continuity mistake: Reese had a lot of food in his bowl (when complaining about the low-fat food she has made them eat), then Lois puts food in his suddenly empty bowl. (00:05:25)
Pearl Harbor - S6-E4
Continuity mistake: Lois and Jessica enter the house after coming back from going to a musical. As Lois comes through the door her purse slips off her shoulder and she catches it around her elbow. In the next shot a second later, the purse is back up on her shoulder. (00:16:00)
Kitty's Back - S6-E5
Visible crew/equipment: A hand is visible on the left edge of the screen when Francis is talking to Dewey through the bathroom door. (00:15:50)
Continuity mistake: At school, Dewey stops the shouting match between the two opponents. In the shots facing Dewey, the boy's arms are held way up high in front of him, but in the shots facing the kids, the boy's arms are down at his sides.
Other mistake: When Reese lights the fuse for the fireworks, Malcolm says the fuse is timed for 20 seconds. When the diving board collapses on Reese, it is around 30 seconds after the fuse is lit before the fireworks start.
Living Will - S6-E12
Continuity mistake: In Season 2: Episode 15, when Francis and a group of people are volunteering at the Lucky Aid, Craig mentions to them that he might've accidentally mailed the marked inventory numbers to his mother. However, in this episode, Craig has never seen or interacted with his mother because his father told him when he was a child that she passed away.
Continuity mistake: Halfway through the episode, the bedroom door is open in the wide shot. In the over-the-shoulder and closeup shots, the door is closed. (00:10:09)
Continuity mistake: Francis calls Hal out to the driveway where two motorcycles are parked. In the first camera shot the motorcycles are parked side by side with the front wheels turned in the same direction. All subsequent shots of the motorcycles in the driveway show them in a different position, one angled behind the other, with the front wheels turned in opposite directions.
Visible crew/equipment: There is a man's elbow on the right of the screen near the start when only Jamie and Hal are in the room. (00:02:49)
Continuity mistake: Hal shows Dewey that he fixed the microwave so that it works with the door open. There is a red cloth inside. Hal then shuts off the microwave and when he and Dewey start talking the cloth changes position from shot to shot.
Answer: It is made up - although it is implied she is Croatian, she never mentions it herself.