I think it is worth distinguishing "conventional wisdom says X" and "the facts are clear that X". Bloodletting was standard medical practice for 100s of years. If you asked a doctor from 500 years ago whether bloodletting helped patients, they would probably say: "the facts are clear that bloodletting helps".

Just in the past few years we've seen some major examples of conventional wisdom being overturned. For example, very early in the COVID-19 pandemic, conventional wisdom was that wearing a mask wasn't helpful. Then the conventional wisdom was that wearing a mask should be obligatory. In 2016, the conventional wisdom was that Donald Trump couldn't win, and that didn't work out so well either.

The real world is often complicated enough that careful analysis is required to get to the bottom of an issue. If conventional wisdom doesn't derive from someone somewhere doing a careful analysis in some way shape or form, I consider it suspect -- akin to an uninvestigated urban legend.

To do a careful analysis you'll want to look at all the important facts, including new facts, and facts that are problematic for your current point of view. If people are suppressing the circulation of important facts by saying "we know these facts are harmful due to [conventional wisdom]", they're interfering with the very process by which conventional wisdom can be made accurate. It's like climbing to the top of a tree and chopping at the trunk below you.

The global war on terror is actually a great case study here. Right after the Sept 11 attacks, it was conventional wisdom that terrorism was a Big Deal, Something Had To Be Done, and people who asked inconvenient questions were Helping The Terrorists. If those inconvenient questions had seen the light of day instead of being suppressed, maybe conventional wisdom would've come more in line with a careful analysis which accounted for all the important considerations, and we could've conducted the "war on terror" in a more intelligent and humane way.

>As for whether a point-by-point refutation is the best and only remedy, that seems to require that the victim automatically have access to the resources necessary to air their refutation where viewers of the documentary will see it. Will the National Review bump an opinion column by a Republican senator in order to publish an opinion column by a Muslim detainee instead? "The remedy for speech is more speech" style defenses assume that everyone has equal access to speech and everyone's speech will be heard equally. Neither of those are true when we're talking about released films.

When it comes to speech suppression I think this is almost always an orthogonal issue. It seems clear in this case that the subjects of the documentary have a big platform -- big enough that they were able to get the film pulled from Sundance. If the film is a misrepresentation, they can use their platform to explain why, rather than using their platform to get it pulled. If Sundance is worried that festivalgoers won't hear their side of the story, they could let the subjects of the documentary send a video of themselves doing a rebuttal, and play that video as an addendum to the main film.