Bin Laden Video Faked?

Neal Krawetz has analyzed the Sept. 11 bin Laden video and concludes that the sections showing bin Laden speaking are recycled from 2004 and therefore the video provides no evidence that he is still alive. He bases his findings on

• Splices. Krawetz identifies 6 splices in the video. But what do those show? Couldn't the video have simply been edited by al Qaeda before distribution?
• Clothing and environment. The clothes bin Laden is wearing are identical to those in the 2004 video. Furthermore, the desk and background appear identical.

  Yet here is Bin Laden in the same clothing, same studio, same studio setup, and same desk THREE YEARS LATER. In fact, his stack of papers that he reads are moved between the exact same stacks. If you overlay the 2007 video with the 2004 video, his face has not changed in three years -- only his beard is darker and the contrast on the picture has been adjusted.
  
  What are the chances of nothing changing (except his beard) in three years? Virtually zero. The clips appear to have been recorded three years ago.

• JPEG artifacts. Artifacts in the video show that the bin Laden image and the border were saved at different times. In fact, Krawetz lists out the order in which he thinks the layers of the video were assembled. But again, what does that show? Certainly the video would have been edited as any border would have been added later. That would cause the two sections to have been saved at different times, and the different layers to be put together.
• Interlaced video. "Both saturation and PCA shows fine horizontal stripes on Bin Laden and the background. These came from interlaced video sources." Yet again, what does that show? Does having the bin Laden images interlaced mean they were shot in 2004?
  

So, of the four points of argument, only one--the physical similarity of bin Laden between the 2004 and 2007 videos--seems valid. But even here, Krawetz leaves a question. He says the only physical difference between bin Laden in the two videos is the color of his beard. Then, if the two videos were actually shot at the same time as he claims, that the color has changed indicates that the color must have been manipulated. Unfortunately, Krawetz admits, "It cannot be detected with any of my tools as being digitally modified." And again, "As far as my tools can detect, there has been no image manipulation of the Bin Laden portion of the image beyond contrast adjustment. His beard really does appear to be that color."

Therefore, the one demonstrable difference between the videos cannot be verifiably attributed to manipulation. One can only conclude that his beard color in the 2004 video was manipulated to make it gray, which seems dubious. (Krawetz posits that the beard "could be a costume mask, or a trimmed and dyed beard." But, that does nothing to explain why the color would be different between the two videos.)