Factual error: Justine and Maria are in Justine's bedroom. Justine is showing Maria the photos on her bedroom wall of her family and school friends. There is a photo of Banksie and Zammo on the wall. These two boys left Grange Hill at the end of series 10. Justine started in series 11, so she would not have known them.
Plot hole: Gripper, Woody, and Randir are suspended from school for two weeks after their involvement in the fight. Woody and Randir appear in the next episode, but Gripper doesn't return until episode 14.
Character mistake: Gripper tells Georgie that he and Denny are bunking off their next lesson to go to the cafe, but they do actually go to their next lesson where they find Randir writing on the blackboard.
Episode #7.2 - S7-E2
Other mistake: When Claire is asking her friends for their dates of birth for her bio rhythm calculator Anita says her date of birth is 25th October 1968, to be in this school year she would have to have been born between September 1967 and August 1968.
Other mistake: Hollo goes into the hall where Perry is with Louise, Cheryl and Julie after Hollo has taken Perry's money for the bet he says "hope you win, Perry". Hollo couldn't know his name when he hadn't met Perry before or been introduced to him.
Visible crew/equipment: When Mrs McCluskey parks in the school car park camera's and crew members are reflected in the side of her car.
Episode #8.9 - S8-E9
Other mistake: When Zammo is talking to Sarah and Mandy in the street, behind them are two women standing watching the filming. (00:07:23)
Episode #2.8 - S2-E8
Plot hole: In this episode Cathy's father comes looking for her, he walked out on his family eleven years ago and had no contact with them during that time. Cathy's mother always told her that her father had died when she was a baby so A) How did Mr Hargreaves know which school Cathy attended? and B) how did he recognize her straight away when he hadn't seen her since she was a year old baby and she was now twelve years old?
Episode #2.3 - S2-E3
Plot hole: Miss Summers tells her class that they have the afternoon off school due to an emergency staff meeting. Penny and Suzi leave the room with the other pupils, Miss Summers stays sitting at her desk. As the two girls are walking down the corridor out of school they stop outside the room that the meeting is in to listen. Miss Summers opens the door and tells them to go away - how did she get to the meeting when she was still sitting at her desk when Penny and Suzi left the room?
Continuity mistake: Robyn celebrates her birthday in episode 12, and as she's in year 10, that would make her 15. However, when she runs away in episode 14, her age is said to be 14.
Episode #1.9 - S1-E9
Character mistake: When Mr. Mitchell is at the civic centre looking for Trisha who is playing truant, he asks the receptionist if she has seen her and describes Trisha as having long blonde hair. Trisha has brown hair.
Outward Bound: Part 1 - S6-E15
Revealing mistake: When Mr Baxter walks into the boys' dormitory, he gets soaked by a bucket of water that is placed over the door. If you look carefully, you can see that Baxter has his eyes closed before the water falls on him.
