Was there a pivotal image that said to you, "This will work—it's going to be great"?
It was the photograph where Jane is reaching out to a baby chimp, and the mother chimpanzee is right behind. It makes them both look so human. And the mother allowed that to happen. It's a humdinger of a photograph. And to have that trust!
That photograph was taken in 1965. I assume the film—and it would have been film back then—was shipped back to National Geographic Society headquarters in Washington by air.
If you were in the field in Africa 50 years ago like Hugo, it might have been months before you could get to an airport and send it back to NGS for processing.