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: When Malcolm is in Stevie's room eating cookies, the cookie in Malcolm's right hand disappears and reappears between shots.
Continuity mistake: During the fight between Malcolm and Spath, Spath goes at Malcolm with his right fist, but the closeup of his hand going towards Malcolm and Stevie is his left hand.
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: During the scene when Lois says that Malcolm is a genius, his arms keep changing position between shots.
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.