Factual error: In the scene where St Matthews is Playing St Luke's in Football you can ADAMS printed on the chin strap of Matt Damon's Helmet. This movie was set back in the 40's or 50's and Adam's was not making those chin straps especially with ADAMS printed on the strap for many years to come.
Continuity mistake: When David Greene first arrives at his new school and is walking down the hallway to find his room, you can see a small piece of paper in his hand, but when he walks into the room and shakes the man's hand, the paper is gone.
Continuity mistake: When the group is deciding who cheated, the bottles and can on the desk change position throughout the scene even though nobody touches them.
Continuity mistake: When everyone is getting ready for the dance, you see the side of Rip's face covered in shaving cream, and when the camera angle changes the shaving cream is gone.
Visible crew/equipment: At the end, when Dillion drives to talk to David, you can see the crew reflected in the rear panel of the car.
Continuity mistake: After they find out that David is Jewish, he goes to his room and finds a sign. He posts a note on the wall challenging the person who made the sign and when the camera angle zooms in on the note, the note is seen posted at a different angle then when he first posted it.
Continuity mistake: When David is fighting the biker in the alley, you can see that the scene was shot at different times. During some camera angles the sky is clear and sunny and during others the sky is gray and overcast.
Character mistake: In School Ties, when they are playing the football game, the coach calls the character of "Chesty Smith" (Affleck) "Benson" instead of "Smith".
Visible crew/equipment: During the football game, in one of the huddles, the boom mike is reflected in Dillon's helmet.
Continuity mistake: When David is still meeting the guys for the first time Mack gets chased out the room. Rip grabs his jacket off his back - when shot from the hall Mack has it back and puts it over his shoulder. (00:15:25)
