Corrected entry: When Harry confronts the bank robber and clicks the empty chamber as if 6 shots had been fired, in truth he had fired only 5.
Corrected entry: The route that the Scorpio makes Harry take to the cross would definitely take longer than 20 minutes. In the movie he runs Harry all over town on a trek that would take many, many hours.
Corrected entry: When Scorpio hijacks the school bus near the end, he says something to the effect that they are going to take Sir Francis Drake Boulevard to the Santa Rosa Airport. Unfortunately, Sir Francis Drake Boulevard doesn't go anywhere near Santa Rosa, it heads west through Marin County and ends up near Pt. Reyes. They should have stayed on the highway and kept going north to get to Santa Rosa.
Corrected entry: On the way to Jaffe's diner Harry passes by a car in which a bank robber is waiting for his accomplices to come out. After he places his order Harry asks Jaffe if this car's engine is running, which he could tell from the exhaust smoke the car is emitting. However, when Harry drove by there were no fumes, only now there are, but Harry hadn't looked back since.
Corrected entry: When Harry drives by a car in which a bank robber is waiting, there is a close-up of the driver lighting a cigarette and dropping the previous one on the ground. Here we count eight other butts, which, even if he is a fast smoker, mean that he has been waiting there for about an hour, which is a bit long for a decent bank robbery.
Corrected entry: On the whole Dirty Harry is a realistic movie, but the way Harry shoots Scorpio without any aiming while Scorpio is holding a boy in front of him is not only something no policeman, not even a tough guy like Harry, would risk, but beyond any fathomable shooting skills (Wilhelm Tell says hi, but even he didn't shoot from the hip).
Corrected entry: When Harry stabs Scorpio in the thigh, Scorpio pulls it out with ease. It should be much harder to pull out a knife that is lodged in your thigh.
Corrected entry: Dirty Harry carries a .44 Magnum, but he uses .44 Special ammunition, which is quite a bit less powerful than the .44 magnum.