Boom mic visible: Visible when Father Bobby visits young Shakes at Wilkinson.
Continuity: Pen disappears from someone's pocket during the courtroom scene.
Continuity: Michael's cigarette swaps sides when hugging at the end.
Continuity: During the lunchroom scene at the Home for Boys, Nokes breaks up the fight, and the boys stand in front of him waiting for orders. During this scene, Michael's hand repeatedly jumps from his nose to his hip.
Continuity: The amount of blood on Michael's face during the scene in the Wilkinson lunchroom.
Continuity: At the end of the movie we see the outside of the courthouse which says "United States Courthouse" which is a Federal Court. The trial took place in a State court not a Federal Court.
Continuity: In the subway train scene, when Michael is talking with Carol, Michael is alternately stroking/not stroking Carol's hair between shots.
Crew or equipment visible: When the boys sit around a table and decide to keep quiet after Wilkinson, the camera's shadow can be seen on Tommy's face and John's back. It moves as the shot tracks around the table.
Continuity: When the hot dog wagon starts to fall down the subway, the umbrella stays on the stairs. Then we see it being crushed by the wagon. Then it's back on the stairs again.
Continuity: John offers Tommy a cigarette from a Marlboro pack in the bar. When Tommy is shown putting the cigarette in his mouth it is clearly a Camel brand cigarette.
Continuity: When the young lads are looking into the Ice Capades' dressing room, the windows are covered by a wire mesh, but looking back at the peeping eye from the inside there is no mesh.
Errors made by characters (possibly deliberate errors by the filmmakers): The priest says that it took Michelangelo nine years to paint the Sistine Chapel ceiling. It took four years to paint the ceiling. (It took an additional four years or so to paint 'The Last Judgement' on the wall behind the altar.)
Continuity: Near the end of the film, when DeNiro's character hands the basketball tickets to Pitt's character in court, Pitt reaches for the ticket twice.
Errors in geography: During the trial, the outside scenes are shot at the Manhattan Municipal Building which house city offices, not the courts. The courthouses (federal and state) and the district attorneys office are located a few block north of the municipal building at Foley Square.
Anachronisms: In the scenes where the adult Shakes and Mike meet in Queens, a train of "Redbird" subway cars is shown passing above them on the "7" line. In 1981, these cars were not yet painted red; they were still painted in their original "World's Fair" colors (turquoise and white) or else were painted all-white.