(at around 1h 30 mins) When Andy is headed to Mr. Simon's house, a white 90s Lincoln Town Car can been seen in the background.
The drum kit cymbals used during the talent show had Sabian cymbals. The company was founded in 1981 and never existed back in 1960's.
The movie opens on May 17, 1965 (date seen on classroom chalkboard). Andy later enters his living room at home where his mom is watching a news report on TV about the war in Vietnam. The reporter's voice (sounds like Walter Cronkite) is clearly heard narrating a retrospective of the events of the Tet Offensive that began in January 1968, and the Battle of Khe Sanh that ended in July 1968.
Norman made a reference to cop-related television programs that feature policemen speaking the phrase "you have the right to remain silent" to criminal suspects. However, the Miranda Warnings were not established until June 13, 1966.
"Teach Your Children" by Graham Nash was recorded by Crosby, Stills, Nash & Young in 1970.