We are video taping an event of which there will be pannelists. One of the pannelists can not sign a talent release form because of his union. The purpose of the taping is to document the event, activities and follow up interviews. This person has agreed to an interview as well, but no release.
The plan is to show this on public access TV, but, we may sell some DVDs as well - mostly to locals (who are in it) and fans of the event.
I think there is a fairly simple solution. Since you are talking about limited sales and broadcast, getting verbal permission on camera will be more than enough to cover you. When you are doing your interview, once the camera is rolling, the first thing you will do is describe your intended use for the video and say "is this OK?" As long as he says "yes" on camera you are more than covered for the limited uses you intend. A verbal contract is a perfectly legal contract.