I agree, stay silent on the book report. If it comes up again, tell your h that your son can choose the person that he wishes to write about. After all, it's nothing more than a book report. It's not a life and death article.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.