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: Thieves make off with 10 million dollars transferred to an offshore bank. The money is shown supposedly in a medium-sized black satchel carried in one hand by one of the accomplices. The largest US bill in circulation is the $100 bill. And one million dollars in $100 bills weigh 22 pounds. So ten million would weigh 220 pounds. There is no way that amount would fit in such a satchel, and much less be carried around dangling by one hand.
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)
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)
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.
Factual error: A CIA officer stops McGarrett and companions from entering a house to make an arrest. The mistakes here are numerous: 1 - The "CIA officers" have protective vests that say "CIA" on them. No such thing. 2 - They are carrying weapons. Only officers in the Security Protective Service and those officers in a war zone carry weapons. 3 - The CIA is not a law enforcement agency. The FBI handles matters domestically. 4 - The CIA's responsibility is to collect intelligence and information overseas. Last I looked, Hawaii was part of the United States. (00:33:10)
Factual error: Higgins gets counterintelligence documents from an operative. The document says "CLASSIFIED" at the top. A real document would have the actual classification, e.g., TOP SECRET - NOFORN; SECRET, etc. on it and not the word "classified." To make matters worse, at the bottom the word is misspelled "CLASSAFIED" (00:27:30)
Factual error: The Five-0 team is discussing the helicopter incident where three people were killed. Junior states that they could find no prints or DNA at the helicopter. Yet the helicopter was full of blood, and the perpetrator (seen later) was covered with bloody wounds. It would have been impossible NOT to find the killer's DNA at the very least in the blood. (00:08:30)
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: 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 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)
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.