When McGarrett leaves his office to look into reports of a suspect on foot, he fails to correctly place the telephone handset back in its rest.
Perky is shot in the chest, but there is no blood on her blouse.
Rolly tells Bancroft to meet at Tantalus Lookout but, they end up meeting at Halona Blowhole. Tantalus is above the Cemetary of the Pacific, and Halona blowhole is near Hanauma Bay- quite a distance apart.
When McGarrett unloads the gun first by removing the magazine, then ejecting the round in the chamber, he has his finger on the trigger. McGarrett as a police officer (and Jack Lord as a gun control advocate), should know that one of the most important rules of gun safety is to keep you finger off the trigger until you're ready to shoot.