personaly, i never realy liked that tutorial anyway.  it doesnt give an example of what HDRI is realy capable of, and doesnt realy explain the settings for HDR maps in blender.

one thing that i have found to help when getting an hdr image is to enable zenup zendown, sometimes hori (horizon) and always blend under the map to tab in the textures box in the world buttons tab.

another usefull thing is to change the colors of the backround.  under world buttons--> world, there are two boxes of color, blender's default for these is one dark blue and one black.  what i have had much success with is changing the blue box to black and the black box to white. 

one other thing that the tutorial doesnt realy explain is which type of texture coordinate to use.  for most hdr maps you should use the angle map (angmap).  hdr files which use this can be identified by a picture with a fisheye lense sphere in the middle.