This is one of the funniest clips in the Anthology DVD series. You'll find it on Part 7, within the first 10 minutes or so. Here they are, The Beatles, attempting to recall whether or not "All You Need is Love" was written specially for the Our World television program.
George: I don't know if the song was written before that, because, we were making an album at the time, so there was kind of, lots of songs in circulation. Paul may know more about that ... over to you, Paul!