If his argument isn't that "it never existed" then he shouldn't title his post "The Curious Case of the Weapon that Didn’t Exist" or write "A military flail is

If his argument isn't that "it never existed" then he shouldn't title his post "The Curious Case of the Weapon that Didn’t Exist" or write "A military flail is a medieval weapon consisting of a short handle attached to a chain, at the end of which is a metal ball. [...] Only problem is: they never existed." or write "the flail was almost certainly an invention of the imaginations of later people." or write "My working hypothesis is that all the flails [...] are [...] fakes." or write "At first that would seem to settle the debate: flails certainly existed, otherwise what could these artists be doing putting them in their art?" (The answer is "depictions of the exotic or fantastical" and the author says: "The artist certainly had quite an imagination.") Why would the author write: "The more interesting possibility is that they were figments of an active artistic imagination, and that the examples we have are artistic or ornamental." and "the original inventors were not weaponsmiths but illustrators" i.e. that not one authentic copy exists. That it was invented in art. This is an absolutely ridiculous suggestion, but it is the title and hypothesis of the writeup. The author is suggesting, explicitly in the quotes I mention above, that not one authentic copy had been originally constructed. (Not that it existed but in low numbers, this is an idea he tried very hard to dismiss.)