Continuity mistake: During entire scene with dancing king Herod and his men, shadows on the floor are at different angles from one shot to another. (01:16:15 - 01:19:30)
Continuity mistake: When Serpico finds three black men raping a girl in the park, one of them cuts the girls face slightly and the cut is very visible. The camera then cuts away then back and the cut and blood is gone. (00:10:25)
Other mistake: Dunnaway fires a warning shot next to her father to encourage him to leave the property. In the sequence just before he leaves she fires one shot and there are two dirt eruptions near his legs.
Visible crew/equipment: When Charles Bronson is chasing Paul Koslo through the flea market, the rooftop mounted camera set up can be seen atop the car.
Revealing mistake: Right at the end when John is dying look at the texture of his blood. It is way too thin, almost like coloured water.
Continuity mistake: In the scene where Ka and Bee jump over the "wall" towards the end after attaching the bomb to the boat, they have nothing on their backs; but when they jump into the water, the 'holder' of the bomb is seen on their backs again and the woman takes it off then.
Continuity mistake: During one of the pool scenes, balls disappear and change position between cuts.
Continuity mistake: Rizzo breaks up the rumble at the pizza joint; in the wide shots when he keeps the goons in check, there are several more unperturbed bottles in the shelves behind Manomozza than in close-ups. Some of the bottles that were in the side shelves in fact have inexplicably moved onto the center one. (00:11:25)
Continuity mistake: When the protagonist dodges the machine gun fire in Amafi's office building, the desk in front of him has a lamp on it in the frontal views, but with the camera placed behind Shaft there is no lamp. (01:39:55)
Character mistake: After Clinton's phone call, Christine talks with her assistant and making fun of the "mourning", she says "We went directly to Streisand's opening at the Sands right from the cemetery." However, in Vegas Barbra Streisand never performed at the Sands; she did the International (then Hilton) and the Riviera. (00:05:15)
Continuity mistake: The attachment to the minisub is inconsistent. It is an open hook first then as it's being lifted it becomes an enclosed shackle looking quite different. Plus a figure now appears on the roof. Ben Gazzara has just gone below. (00:57:42)
Continuity mistake: Some scenes show the actresses in their yellow prison dresses getting dirty, yet a minute or so after this, they're clean again.
Revealing mistake: When The Kid sits next to Dillon at the Bruins game, there are two older women in the background looking directly at the camera and pointing at it, having just noticed that they are being filmed. (01:33:10)
Factual error: James Caan plays a US Navy Boatswain (Bo'sun) Mate. His rank insignia of BM 1st Class should be worn on the right sleeve, but he has it on the left.
Continuity mistake: After spotting her dream house Susan runs to the door. As she approaches the house it's not the same building she spotted from the car. (01:23:50)
Continuity mistake: When Ray and Alex incapacitate the last of the 4 cops, he flips on the ground wearing his hat. When they approach him to finish him off, his hat is at distance. (00:10:00)
Other mistake: Throughout the whole scene when Black Caesar is wounded by the Irish hitman several passers-by can be seen looking directly into the camera, and in many shots people are crowded together on the sidewalk watching the filming. Conversely, the hitman fires a big and loud revolver in the middle of a crossing with dozens of people and cars in close quarters, and nobody bats an eyelid. (00:03:00)
Audio problem: When the king's army officers are talking, the one who criticizes his adviser's mouth doesn't match with what he's saying.