Factual error: In the Brighton street scenes the parading air cadets are wearing service issue pullovers. These were not introduced as part of the uniform until the mid seventies. During the sixties air cadets would have been wearing battledress tunics.
Factual error: In the scene where the Warriors are hiding from the Turnbull A.C.'s under the elevated subway they look up at the train that is approaching the station. The train is marked as a "J" train. At that point they are still in the Bronx. The "J" train never runs in the Bronx.
Factual error: In the opening scene that shows San Francisco scenery there is a shot of a large TV tower called Sutro Tower. The film takes place in 1960 and Sutro Tower wasn't built until 1973.
Factual error: All Borstal inmates were subject to the same mandatory haircut of short back and sides, yet many types of hairstyles are shown in the film.
Factual error: When Holmes gets rundown by the carriage, he gets taken home and Watson ministers to his head wound. Holmes gets up a short time later and refers to the carriage as a hansom, which is a little two-wheeled cab. The attacker drove a brougham, with four wheels and four-in-hand horses. Even with a slightly bruised head, the master of observation would never make this simple yet telling mistake as he's shown seeing the carriage. The type of carriage is vital to the plot later as it suggests the wealth and status of the murderer and it appears to be used to commit the crimes.
Factual error: In the opening credits, the camera is making a slow pan across a suburban neighborhood street following a row of houses. In one the driveways is parked a white 1965 Chevy Impala, although the film takes place in early 1963.