That would be the documentary that appears on the 25th Anniversary edition - The Fear of God.
It was edited for the BBC broadcast and UK dvd and although the US dvd is 50% longer it too has footage missing that appears on the UK version.
Some of the scenes added later were on that dvd in a deleted scenes section and the writer and director have a commentary where they come up with some logic as to how at least one of the scenes could be put back in.
Your Friedkin comments may also have come from the commentary present on the original disc
It was edited for the BBC broadcast and UK dvd and although the US dvd is 50% longer it too has footage missing that appears on the UK version.
Some of the scenes added later were on that dvd in a deleted scenes section and the writer and director have a commentary where they come up with some logic as to how at least one of the scenes could be put back in.
Your Friedkin comments may also have come from the commentary present on the original disc