Danny is seen boarding the helicopter empty handed. Yet, when he sits down with Dean (portrayed by Monte Markham), Danny now has a briefcase with an old fashioned, oversized (even for 1973) tape recorder in it (which is actually larger than the briefcase), when he sits down, to tape the meeting with Dean. Likewise, when he returns to Honolulu, he leaves the helicopter empty handed, yet when he arrives back at Five-O headquarters, he has boxes, ledgers, and other bulky evidence in hand.
When Dean (portrayed by Monte Markham) shoots Fleming, the revolver used by Dean is shown to have a "silencer" (also known as a "suppressor") attached, and the sound heard is the typical "phift" heard in television and movies to approximate what a suppressed handgun shot sounds like. However, this is not possible with the revolver Dean was shown to be using. The very loud (usually from 140 to 160 decibels) sound a typical "unsilenced" handgun makes is due to the detonation and escaping gas from the ignited powder used to expel the lead from the brass and the barrel at a speed usually not less than 1,100 feet per second. In a typical semi-automatic weapon, the first place that the escaping gas can exit the weapon is the same place where the lethal lead is propelled from, the barrel. However, on a typical revolver, as used in this scene, the gas can escape before the end of the barrel, where the silencer is shown to be attached, it can escape from the cylinder. Also, on the revolver shown, the barrel would have to be customized in order to accept a screw on silencer, because the barrel is not threaded.
The "security computer" in Barry Dean's office are just Teac A3300 and Teac A7010 stereo tape decks that go into fast forward when the card is inserted into the reader attached to the side of one of them.
When the guard switches on the "metal detector, he just turns the switch on a Motorola 2 way radio base station.
Barry Dean's corporate helicopter and the HPD helicopter are the same one N8585F.
When McGarrett and Danny go out in the helicopter to retrace the flight, two of the shots of the helicopter in the air show a Hughes 369, not the Bell 47J-2A they went up in.
When Danny is retracing the route he took to Maui, he points out certain beacons that told him where they were. He says that they took off from Diamond Head, and headed south for 12 minutes, then due east, which would take him to Maui. He recalls seeing the light from Kaena Point,which is on the northwest side of Oahu, and nowhere near where he was flying.
When Danny is retracing his route to Maui, he identifies Kaena Point as being on Molokai. Kaena Point is on the northwest side of Oahu.