This is the one I was looking for:
http://www.liveleak.com/view?i=49f_1172526096
BBC reporter in New York reading press release that WTC 7 had collapsed when it's still standing right behind her in camera. Fast forward to about 16 minutes to see it. Just before it really goes down, live line from NYC to London gets cut.
BBC started reporting its fall ½ hour before it actually did.