Highest Castle, Deepest Grave - S4-E1
Revealing mistake: Stock footage turns the doctor's black 1970 Lincoln Continental into a 1950s model when it goes over the cliff, crashes and burns. (00:15:50)
Revealing mistake: Near the end, McGarrett's boat is preceded by the wake of another boat that isn't there when the angle of the shot reverses. The wake belongs to the vessel carrying the camera crew. (00:46:45)
Revealing mistake: When the underwater camera breaks the surface in what is supposed to be open ocean, the domed roof of a Hawaiian aquatic theme park building is visible in the background.
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.