The Wikipedia page on CESNUR makes clear that they happily defend all kinds of despicable cults, JW and Scientology being the least evil of them(!). They have defended several cults that committed mass murder and/or mass suicide.
One of the guys that now co-authored the 'expert opinion' in defense of Dutch JW also flew to Japan (all expenses paid) to defend the Aum Shinrikyo cult that killed 13 in the 1995 sarin gas attacks in the Tokyo metro. His 'expert opinion' then was that they could impossibly have done that, and they were being scapegoated. He later had to admit he was wrong after solid evidence showed that the cult did indeed perform those attacks.
Apparently these guys don't need much to go on to defend evil cults. As one reporter states: 'all the cults know they can count on CESNUR'.
What does that say about the worth of their (very much flawed) 'expert opinion' submitted to the Dutch government?