Visible crew/equipment: When Danno pulls up to the beach house, several light panels are visible, reflected on the surface of his car door.
Revealing mistake: The teaser contains footage of a stunt-gone-wrong. The getaway truck smashes into a mock-up police cruiser that has been secured with a chain to pull it back out of the shot. The chain breaks, and is visible trailing from the bumper as the fake cruiser starts an unplanned roll down the hill. (It went on to collide with and damage two real HPD patrol cars rented for the production).
Murder with a Golden Touch - S6-E20
Continuity mistake: Danno reports that the salvage boat is "The Pacific Pearl." But when we see the vessel, the name painted on its hull is "Louise."
Continuity mistake: Danno drives away from 5-0 headquarters in a 1972 Ford LTD, but arrives at the crime scene in a '73 with a distinctively different front grill. (00:04:05)
Other mistake: The coroner says he strangled the women with his right hand. When he goes to strangle the final victim he uses his left.
Mother's Deadly Helper - S6-E22
Audio problem: Chin says "Telex from Washington"; Steve says "Good, good". Clearly overdubbed. Watch - their lips don't move. (00:40:20)
Continuity mistake: 7-1 "The Young Assassins": The hotel towel draped over the first victim's beach chair instantly changes positions between shots. You can see the words "Aloha, Hawaii" emblazoned on it, until the shot changes. Then it's moved up, and only the word "Hawaii" and the hotel's logo are showing. (00:01:50)
Visible crew/equipment: 7-1 "The Young Assassins": The People's Attack Group van speeds past the camera and briefly captures the reflections of several film crew members. (00:35:05)
Continuity mistake: At 0:48:48 the grave marker is reversed (i.e. mirror image), and when they show the marker again at 0:48:50 it is correct. (00:48:45)
Revealing mistake: In last scene, the killer, Aarons, is shown being led into court handcuffed. When they then film from the back, you can see his right hand free, and he quickly moves it to the other to make it appear like he really is handcuffed.
Plot hole: 8-22 "Love Thy Neighbor, Take His Wife": The police cars speed to Tanaka's house with their sirens screaming, warning him in plenty of time to allow him to escape. Apparently these guys never heard of the law-enforcement standard "silent approach."
Visible crew/equipment: 8-16 "Legacy of Terror": As an HPD cop escorts the old man out of McGarrett's office, he trips over a camera cable and nearly falls. When the actor recovers his footing and finishes his exit, the cast regulars simply pretend it never happened and go on with the scene.
Deliberate mistake: 8-4 "Target? The Lady": During the car chase, a crowd of real-life tourists is standing on the sidewalk, very obviously ogling the film crew as they shoot the scene. The footage was left in to avoid an expensive retake of the stunt chase.
Factual error: 8-12 "Honor is an Unmarked Grave": Marshall has been in Hawaii for only 3 weeks, yet he has his cat, which he brought along, living with him. Hawaii requires a 4-month quarantine on all pets brought in from the mainland. Marshall's kitty should still be in lock-up.
Revealing mistake: 8-5 "Death's Name is Sam": The plane hit by the missile is a little too obviously a still photo with the explosion superimposed over it.
Plot hole: 8-22 "Love Thy Neighbor, Take His Wife": McGarrett has two unexplained clairvoyant moments in this episode. First, he divines that the Indian-style headband is turquoise without seeing it. Then, after the kidnappers' phone call proves untraceable, he somehow knows that it was made from a specific pay phone.
Continuity mistake: 8-9 "Retire in Sunny Hawaii - Forever": When Danno leaves his car, he's wearing a brown suit, but he enters Ellen's office wearing a black one.
Continuity mistake: 8-13 "A Touch of Guilt": The assault is said to have occurred at the Zanza Bar. But when we see the location, the bar is called The Makai Lagoon Club instead.
Continuity mistake: 8-15 "Deadly Persuasion": Danny says he hasn't fired his old 45 automatic "since I got out of the service." But at least two previous episodes had established that he joined Five-O right out of college, and was never (not even before college) in the service.
The Capsule Kidnapping - S8-E22
Continuity mistake: During the airport chase, the airplane the bad guys board has propellers. As soon as it's airborne, though, it becomes a jet.
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.