But basically, we cant be a truth telling machine. We can, however, filter out the obvious noise and hold our journalist partners accountable if we find issues with their reporting. We speak with every reporter who onboards to the site, and reach out when needed.
How will you try to find issues? Many claims are made and accepted as true in the media without any verifiable facts to back them up. There's an inherently political valence to which claims receive this treatment at every level (national, geopolitical, etc).
That claim itself sounds like it could use some verification to back it up.
That said, this is why we vet journalists as they come on. We cannot guarantee that no one will ever get something wrong, but we can limit how often it happens. On Twitter/HN/etc, anyone can post anything and face little to no consequences -- thats how trolling can happen. Journalists have bylines attached, and those mess ups can haunt them the rest of their careers. They don't want to get things wrong. We don't want them to get things wrong either. And if something is wrong, then we put out a correction.
I personally don't think a journalist is "held accountable" if all that's being done is an email to them asking for a correction or clarification in an article.
Generally, corrections and retractions are the responsibility of the editor, not the individual journalist (of course, the editor can delegate the work, but they're still responsible for it). The mechanism and its working is pretty well established, by now.
We have not; though I believe they take a little more of a position than we're comfortable with -- we're looking for straight reporting, without opinion.