Factual error: In Steve's office behind his desk is a model of CVN 65 USS Enterprise. The island superstructure is back to front with the Bridge actually facing the rear. This glaring error is present in all episodes to date.
Factual error: Contrary to what Steve says, the U.S. do have an extradition treaty with France, which has been in effect since 2002.
Factual error: Kono is driving a 4-cylinder Chevy Cruze in pursuit of a V-8 Mustang, and manages to stay right behind it.
Factual error: The aircraft carrier towards the beginning is captioned as being the USS Enterprise (CVN-65), where Lt Rollins is stationed. It is obviously not the 'Big E', but a much smaller escort carrier or amphibious assault vessel. Notable differences are not only the sheer size difference, but also lacks the angled flight deck with the protruding catapult brakes, the second port side aircraft elevator and both the superstructure and bow shape are wrong.
Mea Makamae - S2-E4
Factual error: Near the end as the pallbearers are passing, Joe White and Steve McGarrett salute "uncovered" (not wearing a hat). U.S. Naval personnel are required to be "covered" when saluting.
Factual error: In episode 17, Danny's Camaro is subjected to a number of bursts from a mini-gun, riddling it from stem to stern. In episode 18, Danny's daughter mentions that he had just had it repaired. There is no way an insurance company would not total that vehicle, since it would require replacing or using "Bondo" on virtually every body panel, not to mention mechanical repairs.
No ke ali'i wahine a me ka 'aina - S7-E2
Factual error: Five-0 brings up a map of all nuclear power plants in Western Europe that is completely inaccurate - most of the trefoil markers in Great Britain are placed nowhere near nuclear installations, and has 3 in Ireland (which doesn't have any nuclear reactors).
Factual error: During the show, they flash back to November 1963 and have Don Ho in a nightclub performing "Tiny Bubbles." The problem is Don Ho didn't release that song until 1966.
I Ka Wa Ma Mua, I Ka Wa Ma Hope - S8-E10
Factual error: If you put explosives on drywall it will obliterate it, not put a small hole in it.
Pua a'e la ka uwahi o ka moe - S9-E7
Factual error: A 1932 haulage receipt is shown on screen. It says Hawaii, HI. There was no such abbreviation used for Hawaii until June 1963. The territory was spelled out in full. In June 1963 it was HAW, and then changed to HI in October 1963 with the advent of ZIP codes. (00:38:50)
Pua a'e la ka uwahi o ka moe - S9-E7
Factual error: The episode refers repeatedly to a brand new 1941 Rolls Royce Phantom II. The Phantom II was discontinued in 1936. It should have been a Phantom III.
Ke iho mai nei ko luna - S9-E13
Factual error: Three divers arrive at Neptune 1 submarine station where they test the atmosphere at 3% oxygen, 80% helium, 17% nitrogen. Breathing that much helium would make their voices quite high pitched. But their speech is normal. (00:14:30)
Ke iho mai nei ko luna - S9-E13
Factual error: A Neptune 1 dweller is suffering from a panic attack. One of the Five-O members asks if they have any oxygen. Using pure oxygen at that depth could be fatal. At 14 atmospheres of pressure - the pressure of Neptune 1 - pure oxygen would definitely cause oxygen toxicity. Oxygen toxicity is a concern for scuba divers who dive beyond recreational depth limits, use gas blends such as enriched air nitrox, or use 100% oxygen as a decompression gas. Pulmonary oxygen toxicity causes a burning sensation in the trachea, coughing, shortness of breath, and eventually lung failure. (00:14:45)
Ke iho mai nei ko luna - S9-E13
Factual error: Full aluminum scuba tanks are 1.5 pounds negatively buoyant when full of breathing air. Two of them would be 3 pounds negative. Yet McGarrett is using them to propel him down to 127 meters as if they were very heavy weights. (00:37:25)
Ikiiki i ka la o Keawalua - S9-E14
Factual error: A bomb maker is seen soldering a printed circuit board. He has a soldering iron in his left hand, and a voltmeter probe in his right. There is no reason to have a voltmeter probe on the board. First of all you would need a ground probe as well, not a soldering iron. Second, when you are soldering you need to feed the soldering iron with a soldering wire, which he is not doing. (00:20:15)
Factual error: A defibrillator is needed immediately. Adam runs to a storage closet and rummages around for a while, and finally finds a defibrillator deep under other things. This medical clinic is a public place. No one would ever bury an automated external defibrillator (AED) under other items in a storage room. AEDs would be visible and accessible for just such emergencies, as instructed on the devices themselves. (00:35:35)
E Uhi Ana Ka Wa I Hala I Na Mea I Hala - S10-E3
Factual error: HPD's cyber unit is allegedly tracking an IP address, but the address onscreen starts with 258. Impossible, as IP addresses only go up to 255.
Factual error: A man gets out of his car and identifies himself as a Special Agent. He shows McGarrett a badge and an ID card identifying him as a Special Agent of the CIA. There is no such thing. The CIA does not have Special Agents. They have Operations Officers. And it would be extremely unlikely they would have a badge, as they are not law enforcement officers. (00:01:45)
Factual error: McGarrett is reviewing a brief on a suspected cartel operative. He shows a picture and says it is called a "tela de araña" saying it is a spider web. Wrong. A spider web in Spanish is a "telaraña", all one word. (00:05:13)
Factual error: The plane taking McGarrett from Panama to Mexico purports to be owned by a Mexican fishing company. But the registration number on the plane starts with an N and has 5 numbers and a letter. First of all, a Mexican aircraft would not have a registration number starting with an N. That is reserved for aircraft of US registry. All that aside, the registration number is invalid. US aircraft have at most five characters after the N. The registration - as I suspected - was shown to be in an invalid format when queried in the Federal Aviation Administration database. (00:11:18)
Chosen answer: They are Junior's SEAL buddies.