Continuity: In the beginning when Shaft is walking across a street, an overhead shot shows him walking past a taxi and nearly getting hit by a brown car. However, a street-level shot shows Shaft standing in front of and giving the finger to the taxi.
Crew or equipment visible: The outline of a microphone is visible under Shaft's turtleneck at one point when Bumpty Jones visits Shaft at his office.
Revealing mistakes: A passerby walks out of and back into the frame when he spots the film crew during a scene where Shaft and his friends are sneaking into a building to try to rescue Bumpy Jones' daughter.
Continuity: At the beginning of the movie, in Shaft's office, Shaft changes back and forth between a lighter brown coat and a dark coat. The difference can be seen by noticing the horizontal seam on the back of each coat, one is straight and the other is not.
Factual errors: The month calendar in Shaft's office is January 1971 (February 1971 is also posted on the wall in a "next month" style arrangement). But in Lt. Androzzi's office, the date calendar reads Tuesday January 27 and later Thursday January 29. 27 January 1971 was a Wednesday and 29 January 1971 was a Friday.
Continuity: When Shaft gets hit with the machine gun, one of the wounds is to his head - you can clearly see blood there. Yet after the doctor works on him and gets him patched up, all signs of the head wound have vanished - there's no scar or patch there.