When Brendan is in Tug's trunk on the way to see the Pin for the first time he opens up the trunk to see where the Pin lives. He clearly does not have his glasses on while looking out from the trunk. Yet, in the next scene the camera's vision of the Pin is very blurry until Brendan puts his glasses back on. This makes it impossible for him to have been able to see the numbers on the mailbox without his glasses on.
After Brendan's confrontation with Dode in the football field, he falls on the grass and briefly passes out. When he wakes up and hears Laura's horn, his clothing is dirty. When he reaches the tunnel to meet with Tug, The Pin, and Dode, his clothing is clean.
Brendan calling number on "Halloween in January" party invitation found on Kara's dressing room mirror, his Timex wrist watch reads 10.45, while the background digital alarm reads approx. 11:53.
The second time that Brendan and The Brain meet at The Brain's spot. As Brendan asks The Brain about the words that Emily spoke on the phone, two students walk behind them. A few moments later, the exact same pair of students walk behind Brendan, going in the same direction.
While Brendan and the Pin are having their discussion on the beach
as the sun sets. The sun's level above the horizon changes between
shots.
The newspaper shot Emily Kostach's 'Local Girl Missing' article includes multiple grammatical errors, syntax errors, duplications, and inconsistencies.
The Brain shows Brendan several news clippings, including a reference to a chemical compound 'choleric tricemate' which does not exist.
When Tug shoots Dode you see the puff of compressed air from the squib on the back of Dode's head.
After telling Brendan that he has been included in the team by The Pin, Brendan's watch indicates that it is 12.30 pm. If so, the sun should have been almost above him and not half way up in the sky.
The piece of paper that falls out of Brendan's locker has a spelling error on it, it should be "Sarmentoso", and not "Sarmentosa". This can bee seen very clearly when the camera cuts from the piece of paper to the street sign that has the correct spelling.
When Brendan is talking to Assistant Vice Principal Trueman in his office, a reflection of the boom mic can be seen in a picture on his desk.