When I write hubs, I try to document my sources for any factual assertions I make. Obviously, this practice does not absolutely guarantee accuracy. But one should like to be as accurate and truthful with the facts as possible at the time. Documentation is a practice that we all learned about in school. If something is not common knowledge, you cite it!
This way, when someone wants to dispute a factual claim I have made, I can at very least point to where I got it from: full title of book, author, publisher, and year (this is important because information can change over time, though certain continuities seem to remain fairly stable).
I personally tend not to correct people if they have not asked for it -- most people, I find, don't take it well anyway. If I see a hub with no sources listed, chances are the person who wrote the hub doesn't know where he/she got the information, in which case, there is simply no use in getting into an argument about it. Just let it go.
When we assert 'facts,' whose provenance we are unaware of, we will defend them to the death simply because they are self-evidently 'true,' or 'the truth.'