Continuity mistake: When the fireboat brings Eastwood and Daly out to Alcatraz, Eastwood uses the fire hose against a bad guy in a tower. As Eastwood prepares his hose attack, there are close up shots showing Eastwood turning the hose mount from his right to left, and long shots showing Eastwood turning the hose mount from his left to right.
Continuity mistake: In one scene, the mayor of San Francisco and his aide go to a Giants baseball game at Candlestick Park. When the mayor & the aide are seated and having a conversation, a young man siting a row or two behind the mayor leans slightly forward, looks directly into the camera, and starts smiling and waving.
Continuity mistake: When one of the thugs boots Harry out the door during the robbery scene at the liquor store, he stands behind a closed door holding his shotgun. In the next shot, the door is open and he is now standing in the doorway.
Continuity mistake: When the mayor's car comes to a halt, the terrorists blow up a nearby truck with their rocket launcher. In both long shots of the truck, it is not moving, but in a brief direct shot of the truck as the rocket hits its radiator, it is slowly moving forward.
Continuity mistake: When the mayor is being kidnapped, the terrorists take him away and the mayor's vest is unbuttoned, but later, when he is still being taken away, the vest is buttoned up.
Continuity mistake: When the vicar comes to Harry with the wafer during Communion at the church, you can see the vicar lower the wafer when he recognises Harry, but when Harry says "Remember me, Father?", the vicar is holding the wafer near his face again.
Continuity mistake: Before Harry is about to punch Henry Lee when he captures him at the church, you can see that Henry Lee is looking directly at Harry, but in the next shot he is looking down.
Continuity mistake: When Harry and DiGiorgio are driving to the liquor store holdup, DiGiorgio is hanging on to the light with his left hand, but in the next shot he is speaking on the radio with the same hand.