When Republican vice-presidential candidate Paul Ryan closed his speech at the Republican National Convention in Tampa last week with the emphatic incantation "let's get this done!", the inner pentagram of the Republican party was on its feet cheering its approval.

Cut back to the CNN studio where anchor Wolf Blitzer noted how enthusiastic the delegates seemed, although he also noted there were one or two items the fact-checkers might want to come back on. He had, he said, made a list of "seven or eight points" that might be contentious, but didn't mention what they were. Cut to a panel discussion for instant reaction, cut to Ryan and family looking pleased, cut back to the studio. Still no specifics on those pesky facts.

Meanwhile Democrats and those with reasonable knowledge of US politics were furiously filling the internet with accusations that the speech was at best disingenuous, at worst deliberately misleading. What about the car plant Ryan referred to – mocking Obama for talking about it lasting 100 years, yet it was closed within a year of his becoming president – when the Bush administration had closed it? Or chiding Obama for failing to act on a fiscal report when Ryan himself had sat on the committee which blocked the adoption of its recommendations ? Or his Medicaid calculations?

Back in the CNN studio, Blitzer finally felt comfortable listing the points where Ryan had clearly created a misleading impression, noting that "emails and Twitter" had raised such questions, rather than producers and correspondents. For the viewer, it was puzzling.

A major news network that doesn't say, even as the ovation continues, "hang on a minute", is surely falling short. The reluctance of American journalists to tackle the substantive issues raised by politicians, lobbyists, pressure groups and others for fear of being seen as "biased" forms part of a culture of "neutrality" that is essentially driven by economic forces but which is presented as an ethical touchstone.

"The view from nowhere" is a phrase coined by philosopher Thomas Nagel, which was applied to American journalism by academics and commentators like Jay Rosen and James Fallows. It describes a flawed process of delivering "unbiased" reporting. The "neutral" journalist conveys two sides to an argument without forming a judgment. The theory sounds fine until you try it out: "some scientists believe in the Darwinian theory of evolution, but many other people believe that God created men and monkeys from different pieces of magic clay'. An extreme, and absurd example perhaps, but one which illustrates the fundamental bankruptcy of "the view from nowhere".

The culture that favours "neutrality" over "truthiness" was illustrated by Republican Senate candidate Todd Akin's now infamous assertion that "legitimate rape" carries almost no risk of pregnancy, when his interviewer Charles Jaco allowed it to slip by unchallenged. Again, this local interview rapidly found an international audience through the hyper-connected web of consumers and commentators, making the journalistic failure to tackle this at source even more egregious.

The existence of a "fact-checking movement" which runs parallel to, but is not part of, the press shows how disjointed the process of informing the public has become. So much so that a former public editor of the New York Times attracted some ridicule earlier this year when he asked if it was the job of journalists to be "truth vigilantes".; given the prevailing conditions, however, one can see why he was asking the question even it if was phrased in a rather unfortunate way.

Every one of the 15,000 editors, correspondents, producers, gofers and commentators who packed into the convention last week should be asking themselves the same question. If the job of journalism is to strengthen democracy, and if you can't move in downtown Tampa for accredited press, why did Ryan and his team of speechwriters produce something so wilfully misleading? The ugly truth is, they did it because they could.