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.
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.
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)
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.
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: 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)
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)
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.
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.
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.