This has been noted on several other episodes. McGarrett apparently has more than one blue jacket that differ slightly in shade from navy to royal blue. There are several scenes in this episode where his jacket changes color back and forth between the two. Comparing the color of his jacket to the color of his tie as the scenes evolve shows the difference.
McGarrett and Williams arrive alone at the secluded cottage where the kidnapped journalist is being held, yet two cops step into the room immediately afterwards.
Whilst McGarrett is trying to pursuit a fugitive to give himself up, public and press alike wait behind a police cordon. However, two people can be seen walking along the dock, only a short distance away from McGarrett.
At the close of the episode, McGarrett pours himself and Terri a glass of champagne, despite making it clear on many occasions that he doesn't drink alcohol. However, this is most likely a rule he observes on duty or in formal occasions; here, in a more intimate situation, he's probably more relaxed about it.