As the motto of this site is ‘Fighting Ignorance’, GQ should be moderated for egregious factual error.
I’m not necessarily suggesting the ban hammer - and on the face of it, it could be argued that the discussion format corrects factual error all by itself - and it does, for the thread - just not necessarily for all of the individuals who have participated.
So you could have a thread that begins with someone querying a sciency-sounding factoid they heard on TV or read on a blog - and in general, the thread as a whole will provide a good, factual, reasoned response.
However, there will sometimes be individual posts that are very clearly and obviously counter-factual. These nearly always get corrected in-thread - so the ignorance-fighting value of the thread-as-a-whole is preserved.
But if, as is sometimes the case, the member who posted that counter-factual comment does not return to the thread, there remains a little pocket of unfought ignorance- and (don’t ask for an example, but I’m damn sure I’ve witnessed it) they will repeat the same behaviour again in subsequent threads on the same topic.
Obviously, not all facts are cut-and-dried yet, and some areas of knowledge are highly technical - so in many cases, moderation of the content might not be possible, but so what? Not everything looks like a nail, but I still keep a hammer in my toolbox.
And intervention in an argument might be unfair or plain impossible for someone not experienced in that field - but again, this doesn’t really matter if the parties involved remain in active discussion - we have to hope that sanity and fact would eventually prevail.
As I said, I don’t think this would need to necessarily be the same format of moderation as currently exists for bad behaviour - (although if someone habitually posts unfacts with great frequency, it could be argued they’re being a jerk) - it could be a good deal milder and more supportive - a remedial, rather than punitive activity.
Finally, I’m reasonably sure I will have been guilty of committing a counter-factual driveby post at some point in the past - in this case, I think I would welcome a follow-up visit from the fact doctor.