please tell us where you got this information from. Surely a l5 minute interview with Berg before he went to Iraq would not be referred to as 'unused in the film' - THE FILM means the beheading video, right?
The information regarding the interview with Nick Berg being here in the US was contained in the entire article at Salon. You have to be a subscriber or have a day pass to read it in its entirety.
No, "the film" refers to Fahrenheit 9/11.