Cocoon (1) - S1-E1
Other mistake: After the funeral, McGarrett walks up to his friend. You can see not only McGarrett reflected in the man's shades, but the spotlight illuminating him following him along the wall.
Cocoon (1) - S1-E1
Continuity mistake: As McGarret goes to call the cops, Brent removes the knife from the John Doe assailant's hand. As the angle changes, Brent takes the knife from the dead man's hand again.
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.