Factual error: McGarrett places the kidnappers' ransom tape on the reel-to-reel recorder, and before the tape is threaded or the machine properly turned on, the message immediately starts to play. (00:13:35)
Factual error: Throughout this episode, the Japanese assassins are inaccurately referred to as "the Bushido." They should, as the episode title implies, be called Samurai. Bushido was the revered code by which Samurai warriors lived, but was never an appellation for them. (00:17:30)
The Face of the Dragon - S1-E17
Factual error: Two deaths by bubonic plague, spread by casual human contact, have Five-O scrambling to prevent an epidemic on Oahu. But the disease isn't spread this way (its vector is fleas on infected rats). And since the introduction of antibiotics in the 1940s, bubonic plague has been imminently curable, so there was no need for panic, other than, of course, to make the episode more dramatic. (00:18:00)
Not That Much Different - S1-E23
Factual error: In the final shootout scene at the end, Manning's .38 caliber 6-shooter pistol fires 8 successive shots at McGarrett without being reloaded. (00:45:00)
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.