I can't see this individual sujecting himself to a public debate. He might make a public presentation and respond to pre-authorized questions on the subject of the Society's current position on blood, but not on the past.
If you do meet with him, it would probably be a good idea to get permission to record the interview with him.
The individual will likely state that it has always been a matter of "personal choice" for individuals when it comes to medical treatments.
I would focus on what "personal choice" means for Witnesses in deciding whether or not to have a blood transfusion or what it meant in the matter of transplants. Would a Witness in good standing have accepted a transplant when it was viewed as cannibalism? Would a good Witness be more inclined to accept a transplant today? What would have happened before 1981 to a JW guilty of "cannibalism"?
You will have to learn these subjects well if you are to meet with him and be familiar with their ways of sidestepping issues. They have a way of appearing so open minded and free, when a JW faced with these issues is anything but.
Path