Factual error: Kono gives the operator a six digit number for the public phone. By 1970, when this episode was shot, Hawaii had long since initiated seven digit phone numbers, as had most of the US more than a decade earlier.

Plot hole: McGarrett is hunting for heroin dealers who've laced the drug with arsenic. Yet when he and Chin Ho arrest Harry Parch and find his stash, McGarrett performs the TV cop cliché of sticking his finger into the white powder and tasting it. Even that small a dose of arsenic could be lethal, and seasoned cop that he is, McGarrett would know that.

Visible crew/equipment: Several times in this episode, the side of McGarrett's shiny black Mercury sedan mirrors an entire bank of big square studio light reflectors.

Audio problem: Probably due to poor sound pick-up outdoors so near the ocean, much of the dialogue on the beach house patio is noticeably overdubbed. The sound is often out of sync with the actors' lips.

Revealing: McGarrett paces in his office, and when the shot cuts to a close-up of his feet, the actor's blocking mark is visible, chalked on the carpet.

Visible crew/equipment: The shadow of the boom mike's pole rigging follows McGarrett as he passes the ambulance and coroner's wagon. It disappears when the shot cuts to a different angle.

Revealing: When Sally is driving the blue station wagon full of singing kids, several light reflections on the side of the car never move at all, revealing that it's really a stationary mock-up sitting on a soundstage.

Continuity: McGarrett's left hand rests on the side of the large multi-line telephone as he makes his call. The camera angle reverses, and his hand instantly jumps to a different position, resting on top of the phone.

Visible crew/equipment: During McGarrett and Chin's interview with the Chinese bookie, the boom dips into the shot several times at the very top of the screen.

Visible crew/equipment: The boom shadow is moving back and forth at the top of the door when McGarrett and Danno arrest Wilke.

Continuity: When McGarrett and Danno question Frank's daughter, she has her hands clasped in front of her. When the shot cuts, her arms are suddenly extended down at her sides instead.

Revealing: When McGarrett and the modern-day posse find Frank's euthanized horse, the "dead" animal is quite visibly (and vigorously) breathing.

Continuity: Stock footage turns McGarrett's 1970 Mercury into his old 1966 model when he drives out of the Iolani Palace parking lot.

Visible crew/equipment: When the bad guys pull up to the loading dock warehouse, the door of their shiny black sedan reflects several large round studio lights.

Continuity: The HPD snipers watch McGarrett's office window, trying to get a clear shot at Collins. In camera views from inside the office, there's a coat rack with a hanger on it standing in front of the window. But in all the shots from the snipers' POV, the coat rack isn't there.

Continuity: The bomber wants revenge on Danno for killing his brother, Joey Collins, whose death is recapped in flashbacks to a first season episode in which Danno first killed someone in the line of duty. But in that episode, Joey's name wasn't Joey or Collins - it was Thad Vaughn.

Continuity: The monogrammed handkerchief has cursive initials the first two times we see it. But when Lon gives it to McGarrett, the initials are in block letters.