@garlicmustardweed I don't agree with this. While I'm sure you are correct in your assessment of your former friend, I don't think that every good listener is also a good sharer. Lots of people are more than willing to talk or share every single little thing about themselves but have no interest in others. So it makes sense that there are also people who are excellent listeners but terrible sharers.
This reaction is a little naive. You can't think filmmakers run tape on their subjects 24/7. The cost, both in time and money, would be prohibitive.