It doesn't really matter if it was legally an addendum or not. And to be honest i dont think it was. Most probably it was the psychiatrist the prosecution delegated to produce a psychiatric profile of CB. irrespective or not of the verdict which was not in his hands.
The fact that a psychiatrist spent months going though 20000 pages of documentation on CB to reach a conclusion means much more than an interview where he would most probably not respond. Jmo
Do you doubt that CB is a dangerous psychopath? He has already been convicted for sexual abuse of girls and women and is a convicted paedophile. Would you want him living on your street, close to your mother, sister, wife, partner, friend, daughter, niece?