It's not that, it's a combination of the footage implying it was taken by the D800, and also the possible copyright infringement:
TSO Photography (who did some of the shots from that clip):
"A bit surprised to see Nikon using some of my video clips in the world launch of the Nikon D800 camera in Bangkok on the 7th without contacting me. Especially since Canon is one of my sponsors, and I use a 5DII."
"I want to thank Kimito Uemura & Nikon for taking swift action, and resolving this issue quickly. They have taken every step to have the video removed, and will do everything possible to avoid this from happening again in the future. This matter is now fully resolved between the two of us."