I think that’s because he used a bowl instead of a parabolic reflector. And/or the light was too high. Real beauty dishes are engineered. The bulb placement is relative to the diameter of the dish, the arc, and what they want the spread to look like.
For characteristics of a real beauty dish, check the video: http://www.youtube.com/watch?v=w-cQyJWNvLY
If you want to see the greater detail, the video says they have a Facebook page with the detailed photos.