Continuity mistake: When Lois goes outside to meet Hal at the clothesline, she leaves the door open. In a few shots during their conversation, the door is closed in the background. (00:06:20)
Continuity mistake: When Malcolm goes into the classroom and gives his teacher a hamburger she eats about half of the burger really quickly but in the next shot of the hamburger there appear to be only a few bites taken.
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: When Lois fights with the woman in the mud puddle, the tug of war rope is seen dropped on the ground, and then tense again. This alternates between close and far shots.
Halloween Approximately - S2-E2
Continuity mistake: When Francis walks into the boy's room the calendar says September 2000. In the next shot it changes to October 2000. After that Reece says "No, it really is the 31st" he flips up the September page of the calendar to October. (00:06:15 - 00:07:15)
Continuity mistake: In the bowling alley, the design above the pins is blue and pink pins. While in the back of the bowling alley, above the pins is a different design.
Continuity mistake: In the side of the story when Lois takes the boys, Malcolm has some kiddy bumpers put in to help him bowl. In the next scene when Reese is about to tell Beth the joke, you can see the lane which Malcolm was just at but there are no bumpers in the gutters. Then later when Malcolm stands up to Lois they are back in the gutters.
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.
Factual error: It's very very unlikely that police would chase all those women through town (even take helicopters to arrest them) just for making noise on someone's property for couple of minutes.
Answer: Francis is only allowed to talk on the phone at school for three minutes a day. I think the code gives him free access to talk to his girlfriend.