Bradshaw is indeed an excellent source for understand dysfunctional families; as someone who grew up with a narcissistic mother, I can attest to how she saw anything we did as children or adults as a reflection on her. It may be that Paulus, as well, operated from this same enmeshed perspective--that if Joran was held responsible for what happened to Natalee, it would reflect on his own status as a member of the legal community.
The other way to look at it would be to figure that a child is his or her own person and must be held accountable in order to learn that actions have consequences--legal, moral and social consequences. And when people escape legal consequences, the social ones often kick in (e.g., O.J. Simpson and Steeler QB Ben Roethlisberger, who wasn't charge with sexual assault for his latest bit of bad behavior but is pretty much as popular as a skunk at a garden party.)
My bolding
Anita did say that even though they had problems with Joran pre Natalee, Paulus didn't want Joran to get help after Natalee disappeared because it might make him look guilty.