After the opening titles, a high-angle shot shows eight or nine police officers at the base of the sniper's hill, moving forward behind three rolling police cars for cover. There is a black unmarked vehicle around which their cars move, and McGarrett - unmistakable in a slate blue suit and with his pompadour - stands near the left rear of the vehicle. A ground level shot shows that the black car is a Mercury, as well as the last three or four letters of the license plate. Then there's a cut and McGarrett - in that same black Mercury with the same license plate numbers - arrives on the scene with sirens blaring as if for the first time.
In the beginning when the sniper is firing at the policemen and their car, the camera is supposed to be giving the shooter's point of view through the rifle's scope. However, the view as shown is from ground level instead of from the sniper's location high up on the hill.
Before the opening credits, three police cars are being rolled into position, McGarrett and his car are clearly there. During the credits McGarrett is driving and then arrives...again.
When the Honolulu police cars arrive, they are all 1970 Ford sedans (side by side headlamps) with black wall tires and dog dish hubcaps. When the police car is being taken out with the wounded officer, it is a 1967 Ford sedan (stacked headlamps) with full wheel covers and whitewall tires.
When the sniper is getting ready to shoot out the tire on the rescue police car, he clearly loads a blank round into his rifle.
Duke's last name in this episode is Kanaha. His last name should be Lukela.
Danno was shot in the right shoulder. By all accounts, he should not have been able to take a shot at the sniper since he is right handed.
A psychiatrist arrives and fills in McGarrett on Shem's condition. He mentions an incident in Vietnam, then he tells about a second incident at the University of Hawaii not one year sooner where Shem shot up a dozen windows in a woman's dorm. It is surprising that McGarrett and Five-o did not know anything about this incident.
At one point when the police helicopter is landing, the co pilot spot is clearly occupied by a woman in dark glasses who is not seen to have any part in the story, yet it is "Danny" who exits the helicopter in the next shot.