Yesterday we published a story about a man who re-grew a tip of his finger using "pixie-dust" supposedly sent to him by his brother who worked in a regenerative medicine lab. By now the story has largely been discredited. In our defense, when we saw the story on BBC and other respectful outlets, we did not publish it right away. We sat on it for 5 days or so, awaiting a press release from the University of Pittsburgh. When it did not materialize, without realizing that the story has been...