How to best determine if a video has been faked.

BStorm writes: The Toronto Mayor Rob Ford has been making a headlines around the world, for allegedly smoking crack. This story was first broken by gawker.com, which is now crowd-funding $200,000 to buy the video in question. What do you look for to determine if a video has been faked? Of course I am only interested in only the technical details and not the tawdry details related to this case ;) I live in Toronto, so the video still frame posted on Gawker certainly does look like Rob Ford.