The damage wasn't nearly as bad as the articles would make it appear, and the healing process was, according to one hand surgeon, completely normal.
The story was picked up by BBC, CBS News, and Popular Science, among other organizations. However, none of these articles shared pictures of the before and after.
The Guardian (NSFW) also picked up the story in a series called Bad Science and had a picture of the before and after of the damage. The writer was also immediately skeptical of the story.
Now firstly, if you look at the pictures accompanying this column, you will see from the "before" image that there is no missing finger, so we might naively intuit that there is no "missing finger grows back" story to be written. In fact, from the grainy images and scant descriptions available - despite blanket news media coverage, including television interviews - it seems this bloke lost about 3/8 of an inch of skin and flesh from the tip of his finger, and the nail bed is intact.
If your experience of rollerskating injuries is not enough, Simon Kay, professor of hand surgery at the University of Leeds, saw the before-and-after pictures, and says: "It looked to have been an ordinary fingertip injury with quite unremarkable healing. This is junk science."