The guy who shot the video said it was fake, and said he shot the vest, then put vest on kid.
He said he DID dig the bullet out of the vest on camera, that quickly though.
If you read the comments the video up loader even says he shot the vest, THEN had his kid wear it. At that point he shot at him with a blank (ever see the movie The Crow? Yeah not a good idea), and then removed the slug.
Dont believe everything you see. It even sounds like a blank.