When Rachel is telling Shane that she has made a mistake in marrying him, in the first wide shot of Shane sitting on the chair next to the night stand you can see knife on the night stand and the tissue box behind the lamp. In the next wide shot the knife is gone and the tissue box is next to the lamp. In a later shot as Shane stands up, the knife is visible and the tissue box is once again behind the lamp.
Police cars on Maui say "Maui Police" on the door. On the show they say "Island Police."
When Armond is talking on the phone at the reception desk, he's holding the receiver behind his ear. This is actually a common method of using a phone receiver by people who are constantly on the phone and yet are unable to use headsets, as it reduces pressure on the ear.