I do find articles like this ever so interesting. But there are a few points to be made. First, the Nikon competed with the Leica range finder cameras. Great truth, during the Viet Nam war, the only two cameras that survived the jungle environment were the Nikon with Titanium shutter and the Leica with it's specially made rubberized shutter.*
Also, keep clearly in mind that the Leica had a modified shutter introduced back in 1931 that had a throw out bearing system that helped ensure shutter vibration reductions, this gave the image sharpness, and was vastly improved at both high and low speeds. Leica bodies are world renowned for this feature, helping photographers produce sharp images on longer exposure speeds, so no dough Duncan used a Leica camera body because Nikon and every camera maker never took the steps to add this critical improvement to any other camera in the world.
Another point of note, the pre M model cameras were so well made that if the camera (both body AND lens) ended up in a shallow body of water, they were regarded as water proof! I myself have pulled out of a tide pool several times my Leica IIIC with Elmar 50mm f 3.5 lens some as deep as 3 feet and the body was still sealed, and it took me several minutes to retrieve the camera. This is entirely due to the high manufacturing quality of both design and manufacture of Leica cameras. I would venture to guess that the rangefinder Nikons were made to the same quality. But I would never expect a Nikon F body to survive a dink in the drink. I say this because a photographer in the field (especially in a jungle environment) would need a camera that was virtually water resistant.
As to Duncan and his use of the Nikon 50mm f 2 lens. Well, he was obviously a misinformed fool, in Japan the Leica 50mm f2 Sumicron is the water shed lens for sharpness and the best boka of any lens it is tested against.
It is similar to reading an in depth article about the best enlarger lens published back in the day by Modern Photography magazine. In the test a bevy of experts test enlarging lenses and decided to 'standardize' the test using an Omega D enlarger. The Leica Focomat lens should have been excluded from the fools test, but no they tested it using the standard Omega D enlarger. Several of we readers pointed out the glaring fact that of course the Leica Focotar was a not as good, it was never designed to work well with such crap glass condensers. Leitz provided a condenser for their Focomat enlargers of the same standards as their optical lens and with the Focomat enlarger condenser the Focotar made the Omega D condenser look like a coke bottle bottom, vastly better performance of B&W and color print images.
So when you read these 'wonder' stories be vary careful, they are often poorly researched and don't hold up under scrutiny.
May I remind the reader of the lovely NASA event. Nikon designed and sent into space a quad Nikon package back during the astronauts space walks. One was out using the Nikon cluster and after a few frames it jammed, and the astronaut tossed it into space with the comment, "So much for Japanese junk, pass me the Hasselblad." This was on an open mick and the Nikon people were furious, but they learned their lesson and then began working with NASA and heading their input about space gear.
Also, please keep in mind that the Nikon camera was developed as Japan was at war with the Asian countries. To think that they just had a come to Jesus notion about putting a titanium shutter into their camera back when they were putting cameras into the Pacific jungles, and not the usual cloth shutters that die from rot in jungle environments, if you believe that you are desperately in need of help. It was no mistake that they made a metal shutter, and the German Leica shutter curtains were already in the Pacific. Perhaps they could not make a shutter as good as the Leica shutter. Remember, the history of the world's cameras were driven by a long history.
Then ask yourself, why is it that all the films depicting cameras and photographers using 35mm cameras seem to almost always have Leicas in their films. Because the Leica is the gold standard of 35mm photography. Writing books and articles about gear is rather odd, but trying to blow smoke up people's asses about a piece of equipment as the water shed of photography you need to be careful or you will get burned.
* Please note that US military encouraged that Leica camera gear was not a good choice for the Viet Nam theater as the optics that were E. Leitz were so excellent that the optics were found to be used in the manufacture of sniper scopes by the North Viet Nam Government. The US worked at restricting the introduction of optics to countries that would import certain optics to the North. This may appear weird or bogus, but keep in mind that A Leica can not truly be stolen, all lenses and equipment from E. Leitz is registered and tracked, so any equipment that is stolen can be recovered and returned to the registered owner, even years later. The control is in that any parts for repair must be checked in through the Leitz company. My photography gear is registered with E. Leitz.