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.