Factual error: In the scene where the mobsters are chasing Carlito, they chase him on to subway and are about to get him when some New York City Police Recruits also board the same subway. The mistake is that this cannot be possible because New York City had a hiring freeze from 1974-1980, and the movie takes place around 1975, thus there could not have been any recruits around that time.
Factual error: In the scene where Al Pacino is talking on the phone in a phonebooth, you can see that the cars passing on the street behind him have rear window break lights. This movie is set in 1975 and rear window break lights weren't put into use until they were government mandated for the 1986 model year.
Factual error: As Carlito is being carted off, the camera pans across an intravenous line in his hand. The end that is taped to his hand is actually the drip chamber, which pierces the bag or bottle of fluid, not the skin. Also, paramedics would not "stick" a patient there; there are no major veins in that part of the hand.