Continuity mistake: Throughout first season: Due to stock footage spliced in from the pilot film, McGarrett's '68 4-door Mercury sedan often peeled away from the Ionali palace and then turned into a '67 2-door coupe as it cruised down Honolulu's streets.
Audio problem: Throughout series: "Hawaii Five-O's" favorite sound effect was squealing tires, and the effect was nearly always added whether McGarrett's big black Mercury actually "peeled out" or pulled away at a normal speed. More than once, the tire squeal sounded when the car was sitting on beach sand. Nice trick - if you could do it. But alas, you can't "burn rubber" on a beach.
Deliberate mistake: Throughout series: Five-O was said to be Hawaii's state police force, and was shown headquartered in the Iolani Palace. For decades, tourists were disappointed to learn that in reality, Hawaii had no state police, and that the palace was a state museum, not a state police station.
Revealing mistake: In the intro, one of the scenes involves a revolver being loaded as the cylinder is spun. The bullet being loaded and all the others have already been fired - there's a firing pin mark on each primer. (00:00:55)
Answer: He was fired. He never really appreciated his character. He felt Kono was portrayed as a big dumb Hawaiian and that the stereotype was racist. He also felt underutilized. He was fired after a heated argument with the show's publicist regarding his character. It seems there's not much details given regarding the incident or the firing, so it's seems possible he upset the show's producers as well.
Bishop73
No he said something derogatory about one of the Jewish producers that's why he was fired.