Continuity mistake: When Lois and Hal work to draw up their will and then argue about Francis, Lois' hair changes repeatedly when the camera angles continually change.
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.
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.