I don't have issues with the casting but certainly there are parts of the episode that could have been executed better.

As far as the salute, it's happened in prior seasons. I'm not sure exactly when it started, I think I remember seeing it as early as Season 4. I think it's because he's the highest ranking police officer in Hawaii (i.e. State police outrank the city police). Not sure how this works in the real world honestly (that's another thread because what I have to go from is two different states and they're as different as night and day) but I know for a fact Hawaii is the only state without State Police!