Visible crew/equipment: After the fight when the Brookies attempt to steal the cash box Mr Baxter takes it away, there is a boom mic shadow on the wall behind him.
Other mistake: Tucker, Alan and Tommy miss the bus because the driver won't wait, a few minutes later the next bus arrives and it is the same vehicle as the previous one (registration number AML3H).
Visible crew/equipment: When Tucker, Alan and Tommy arrive late for assembly you can see a reflection of a sound man holding a boom mike in the door window.
Episode #4.4 - S4-E4
Continuity mistake: When Mr Hicks says "Move it, Stewart!" when Stewpot is climbing a vaulting box, Hicks is holding a basketball and his arm is stretched out, but when we see Hicks in the next shot, his arm is now by his side.
Plot hole: In this episode Mrs McLusky is horrified when Mr Sutcliffe suggests staging a girls versus boys contest and tells him that the school does not want to promote sexual inequality, but two episodes earlier (4-16) Mrs McLusky wouldn't let Trisha Yates choose technical drawing as an option, as it was classed as a boys' subject.
Plot hole: Doyle steals Alan's judo suit when he inadvertently leaves it in the corridor. Doyle tells Robo that he will leave it in the bike sheds overnight and will sell it to Junky Mead tomorrow. The next day Tucker arrives at school having bought the suit and says he saw it in Junky Mead's shop yesterday and bought it on his way in to school that morning.
Revealing mistake: When the drunk Andrew is asleep in the boys' toilet cubicle, the wall shakes when Tommy shuts the outside door when Alan and Justin leave.
Episode #4.1 - S4-E1
Continuity mistake: The fire alarm sounds and the school is evacuated, three shots are shown of pupils running down the same staircase - in every shot it is the same pupils descending the stairs three times.
Episode #4.7 - S4-E7
Visible crew/equipment: After Rosie and Suzi come out of Mrs Mccluskey's office, as Suzi says "hey Rosie" there is a boom mike shadow on the wall to the left of the door, then when Suzi goes back into Mrs Mcclusky's office there is another boom mike shadow on the wall.
Episode #4.6 - S4-E6
Continuity mistake: When Mr Sutcliffe asks Tucker if he knew who was responsible for the vandalism, Tucker's jacket is only on his left shoulder. In the next shot, Tucker now has the jacket fully on.
Continuity mistake: The location of Mrs McClusky's office in the school changes during this series.
Continuity mistake: Mrs McCluskey tells Gripper he is suspended until the end of term but he appears in the next episode.
Continuity mistake: Pogo throws the chair at Gripper legs first but when it goes through the window it has turned round as the chair backrest hits the glass.
Continuity mistake: In the second scene in the school corridor two girls are walking in front of Alan and Tucker, one wearing a black skirt and a black and white top and the other wearing a blazer and a black skirt. They walk up the stairs as Alan and Tucker stop and chat, a few moments later the same two girls are now behind Alan and Tucker and walk past them in the corridor.
Continuity mistake: Doyle's mate Robo's full name is Robertson in this series, but in series one it was Robinson.
Episode #4.2 - S4-E2
Character mistake: In the meeting, Susi says that Penny Lewis and Rosie Spencer got in trouble during the previous year for writing a libelous article in the school magazine about Micky Doyle, but it was actually Penny and Chris Dukeson that got into trouble about that article about Doyle.
Episode #4.4 - S4-E4
Continuity mistake: When Mr Hicks says "I said I didn't want to see these rags again, Marks", you can see that there is nothing behind Marks, but in the next shot a white shirt is behind him.
Visible crew/equipment: When Tucker shows Alan his new judo outfit there is a boom mike shadow on the doors behind them.
Episode #4.6 - S4-E6
Continuity mistake: Tucker, Benny and Alan are in the hall for Mrs McClusky to announce the winner of The Competition to design the front cover of the school magazine. The shots alternate between Tucker and co and Mrs McClusky - every time the camera is on Tucker, Benny and Alan there are different people standing in front of them.
Episode #4.4 - S4-E4
Revealing mistake: When Mr. Baxter punches Mr. Hicks you can see that Baxter's fist passes in front of Mr. Hicks face and dosen't actually hit him. Also Hicks' reaction is too late, and his head moves after Baxter's fist has passed him.