Continuity mistake: Danno kicks one of the bad guys out of the van, leaving the rear doors swinging open. But when the shot immediately cuts to an exterior view of the speeding van, the doors are tightly shut again. (00:35:00)
Continuity mistake: Stoner strikes Danno across the right cheek. But in the next shot, he's bleeding from the left corner of his mouth. (00:29:15)
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.