Continuity mistake: When the "Krelborne" teacher comes to the house to tell Lois that Malcolm is gifted, Lois comes to the door naked and puts her arm up on the doorway. On the shot from behind she has her hand low (about where her waist is) from the shot from the front she has her hand up high (above her head).
Continuity mistake: When the boys are wrapping their parents present, Dewey is holding a bow in some shots and not holding one in other shots.
Continuity mistake: This mistake happens in the scene where Dewey bumps his head. In one shot, Lois puts her hand on Dewey's shoulder, and in the next shot, her hand is on his chest.
Continuity mistake: In the scene where Lois and Hal tell Malcolm he is going to the "special class", Hal notes that the pitcher of iced-tea he makes is always empty, and says, "Look at that - gone," before placing the lid back onto the pitcher. Yet, when it cuts to the wide shot of the table, the pitcher lid is by Hal's elbow. (00:17:50)
Continuity mistake: While Dewey stands on the table, Mrs. White (Bea Arthur) dips her finger in the bowl of chocolate and draws a mustache with it on Dewey. In the following shots the chocolate on Dewey's face differs.
Continuity mistake: In the escape scene when Hal runs out the store his boss presses a button to lower the shutters. This causes the pencils to fall out of the cup but in the next shot the pencils are back in the cup and roll off the table into the fan.
Continuity mistake: When Francis gets pulled over, his window is open and closed between shots.
Continuity mistake: In the scene where Lois and the boys are in the clothing store, Lois piles a bunch of clothes in Reese's arms. The clothes change in his arms from shot to shot.
Reese Cooks - S2-E18
Continuity mistake: During one of Reese's cooking classes, Hal puts some bread into a toaster. It then cuts to a shot of Reese. When it cuts back to Hal, the toast that pops out of the toaster isn't the same shape as the bread he put in.
Continuity mistake: When Julie passes through the kitchen to get Malcolm, Dewey and Egg are in there cleaning the floor they have suds all over the floor, When Julie runs back through after seeing Malcolm in his underwear she slides across the floor, The floor is still completely covered in suds but when she gets up if you look in the background you see the floor with hardly any suds anywhere. She could not have soaked up all the suds when she slid across.
Continuity mistake: When Lois is in the bath tub soaking after getting upset about the family wanting to go to the funeral. Dewey comes in and ask for juice. When they are on Lois(front view) the suds barely come to the top of her breast. When the show Dewey (side view of Lois) The suds are all the way up to her shoulder.
Continuity mistake: When the Tarantula is put on Hal at the zoo, the shot is only of a yellow shirt with the tarantula crawling on it. When the shot changes to where they show the whole Hal, you can easily tell that the tarantula is fake - it is larger than it was and is in a different spot on Hal's shirt.
Continuity mistake: When Lois is packing lunch in the blue cooler her hands go from on the side of the cooler to down by her waist in one frame to the next. No time for her to move it.
The Bots and the Bees - S1-E14
Continuity mistake: In the scene where Malcolm and the Krelboynes are talking and watching Robots after the opening credits. There is a blue schoolbag on the table but after it is gone, but when we see the table again the schoolbag is there again.
Continuity mistake: When Reese pushes off the table, he knocks one of the place mats out of place. In the next shot, it is where it's supposed to be. This switches back and forth in the scenes. (00:01:27)
Continuity mistake: When Hal is swerving into and away from the bee, during the close-ups, there is a white van behind Hal's car. In the wide shot, there is no van. (00:20:04)
Hal Coaches - S3-E16
Continuity mistake: After Malcolm pushes the computer off his desk, you can see it still on the desk in the next shot, when he says "this means nothing." (00:17:17)
Continuity mistake: Craig mentions that he must have mailed the numbers from Lucky Aide to his mother, but later in the show (the episode with his fit dad), he doesn't remember his mother.
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.