McGarrett's suits changed inconsistently. In this story he wears only two suits, a tan one and his customary blue one. Every time he's at the Hilliard estate he's wearing the tan suit making it look like he inexplicably changes from his blue suit just to go to the estate. It's likely that all of the scenes at the estate were filmed at one time without McGarrett changing his clothes to maintain the continuity of the blue suit he wore in his office.
McGarrett jumps into a 1968 Mercury Marquis two-door hardtop and drives off quickly. When he arrives - following Danno in his 1971 Ford sedan, he is suddenly behind the wheel of a 1968 Mercury Park Lane four-door hardtop.
At the end of the show, it seems implausible that the approaching helicopter fails to observe Danno, Kono and Chin Ho on the beach.