Factual error: The film takes place in a private boarding school the 1950's, however one of the students is studying from a 1980's chemistry textbook. The obvious giveaway is that the spine of one book shows HBJ as the publisher. Jovanovich was not added to Harcourt Brace until the 1970s.
Continuity mistake: Before going to the theatre to watch Neil's performance, the boys are grooming themselves at the school. Todd has combed his hair backwards and styling remedies has been applied. But when the group are about to leave the theatre after the play and Neil and his father passes them at the entrance, Todd has his regular hairdo again.
Continuity mistake: When Neil is talking to Todd about doing the play, Neil takes off his jacket. In the next shot, he's holding the jacket differently.
Audio problem: The first time all friends are in the bedroom together Charlie says "Unless you're a genius like Meeks." Meeks replies "He flatters me so I'll help him with Latin." Halfway through this sentence the shot changes to a sideway shot of meek and his mouth isn't moving.
Continuity mistake: At the very end, about 14-15 students are seen stepping to the tops of their desks. The last shot before the credits, however, shows only 10-11 students on their desktops.
Audio problem: In the scene where Todd is in the principal's office with his parents and the principal, and is is being asked to sign the paper, during the shot of Todd looking at the paper, his father's voice says," I've had enough, just sign it", and it is very obvious that line was added in because it sounded like it was very distant or over a radio or something.
Factual error: Keating misquotes Whitman's "Song of Myself". The word "rooftops" should have been "roofs". An English Lit teacher of his caliber would not have made this mistake. This is a deliberate mistake on the part of the filmmakers.
Other mistake: The ripped-out section of the poetry books looks to be at least 15-20 pages, yet when the waste-basket is passed around, each boy only tosses in one or two sheets, and the floor is no longer littered with paper.
Continuity mistake: When Knox is trying to talk Chris into going to the play with him, for about four shots between the two of them it changes from snowing pretty hard to not snowing at all.
Continuity mistake: Pitts jumps off Keating's desk twice, which would not have been necessary.
Continuity mistake: The first day of school in Neil Perry's boarding room. Charlie Dalton tells Neil "rumor has it, you did summer school." Neil replies "yep, Chemistry." When the chemistry teacher is handing out assignments and textbooks, Neil can be seen sitting in the class. He should have already completed chemistry.
Audio problem: In the classroom when Keating says, "Armies of academics going forth measuring poetry.", it is obvious that this is dubbed over because his mouth doesn't move correctly with the words.
Audio problem: When Chet is pummeling Knox, Chris pulls him off yelling "Stop it!", but her mouth doesn't move.
Character mistake: Meek's first name is spelled in the credits as "Steven"; however, the letter being signed by the students accusing Keating of misconduct shows the spelling as "Stephen."
Continuity mistake: When Keating tells the students to draw a graph, they all follow him step by step. For a specific shot, Meeks mimics what Keating writes on the board and draws a bar graph and colours it. Problem is, Keating does not draw the bar and colour it until a shot later. The movie should have been edited the other way around.
Continuity mistake: During the final scene when the boys stand up on their desks, the boy with dark brown hair stands up twice. After Pitts stands up we see him contemplating, then when Meeks stands up he is visible standing up already, but then seconds later he stands up again.
Chosen answer: It is a classroom exercise. He is being followed by pupils and is reinforcing their latin vocabulary by taking them on a tour of the garden and showing them the things that the words actually relate to (edificium = building, flora = flower etc.) This contrasts with his earlier behaviour when he simply had them mindlessly recite conjugations (amamo, amamas, amabat). The point is that this illustrates how the Latin Master has been affected by his contact with Keating and has become a better teacher as a result.
Oscar Bravo