The building that "played" the Honolulu Judiciary Building is the Honolulu Hale, located at 530 South King Street in Honolulu. This building is the seat of government of the City and County of Honolulu. The chambers of the Mayor of Honolulu as well as the Honolulu City Council are located there.
When the letter from the separatists arrives, the governor says "The life of the land is perpetuated in righteousness"...This is the state motto of Hawaii.
This time McGarrett takes a ride in a Bell 47J-2A to nab the would be sniper and keep him from shooting at the bomb disposal personnel and exploding the bombs. This very helicopter is still alive and well in New York.