This is a german documentary about the "wonderman" Mirin Dajo from the Netherlands, whom David spoke of during the interview. No english dubbing, I'm afraid, but the original footage speaks for itself. These clips are probably part of the "silent movie" David saw. The title of the documentary translates to "the power of mind over matter".
(edit) WARNING: this contains footage of a man being pierced by swords. Not suitable for children or grown ups who are easily scared. Do not, repeat, DO NOT try this at home.
And on the late Philip Coppen's site, I found this article (it's really sad about him, I think Coppens was very thorough and insightful as a journalist and commenter on these subjects):
Mirin Dajo: Wonderman
Despite many attempts to announce Dajo a fraud, with this kind of evidence (the footage and the x-rays) I can't really see how it could just be explained away. The way it looks to me, Dajo should have been part of the X-men or something.
Astonishingly (or maybe not surprisingly, if you know how scepticism works around here), his demonstrations and the footage are absolutely unknown here in Germany nowadays, and everybody I talk to just seems to think "it must have been trickery somehow, so why bother".
EDIT: and we do have a thread about him on the forum, which has unfortunately been overlooked as it seems:
Strange Character - Mirin Dajo | The Paracast Community Forums
I posted the video on that thread, so maybe we should discuss the case there.