A Bullet for El Diablo - S6-E10
Factual error: Che makes the voice-print comparison using a polygraph machine - a device used for lie detection, not voice analysis. (00:36:30)
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."
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).
Audio problem: In the film left behind by the killers, the two men in the picture can be heard talking - but their lips aren't moving.
Continuity mistake: At the airport security checkpoint, Sam drapes a garment bag over the counter, but leaves after the inspection without taking it. Next shot, though, it disappears. (00:44:30)
Other mistake: The CSI technician dusting for fingerprints on the gun isn't wearing gloves. He proceeds to pick up the gun in his, ungloved hands and hand it to an ungloved police officer thereby adding their fingerprints to the gun. Very sloppy police work.
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)
Visible crew/equipment: When Danno pulls up to the beach house, several light panels are visible, reflected on the surface of his car door.
A Bullet for El Diablo - S6-E10
Plot hole: During his investigation, Danno learns that the kidnapped Maria never wears make-up. Yet in every single shot we see of her, Maria is far from cosmetics-free. She's wearing very heavy eye make-up. (00:34:40)
Murder is a Taxing Affair - S6-E6
Revealing mistake: A bad matte superimposed over Cavel's rearview mirror makes McGarrett and Danno, who are actually in a car behind him, appear to be sitting in his back seat instead.
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)
A Bullet for El Diablo - S6-E10
Factual error: Pepe and Carlos are driving a '62 Chevy. When they watch Ramos' motorcade pass, there's an insert shot of a key in the steering column as they start the car. In a 1962 model, the ignition would have been on the dash, not the steering column. (00:13:15)
Revealing mistake: Listie was supposed to be dead, but you can see his eyeballs moving under the lids.
Character mistake: McGarrett mispronounces his old friend Cargill's name in the bank vault scene, giving it a soft G and calling him "Car-jill." Earlier in the episode, and in all the scenes after this, he correctly says "Cargill" with a hard G. (00:17:00)
A Bullet for El Diablo - S6-E10
Continuity mistake: When Rita shoots him, Ramos dies face up on the floor, and she flees without touching him again. When McGarrett finds the body, it's lying face down. (00:20:05)
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.