They have Stockholm Syndrome - and they don't even know it.
Don't get me wrong on this, as I am not excusing the elders involved. But that's what it is- they are mind-controlled into thinking they are doing the greater good by protecting the organization before the individual. They think that reporting all to Headquarters is their obligation to God and they are "obeying God before men."
As far as "clergy penitent privilege " goes, I don't remember any details, but I think it has been shown that this does not apply when a danger to people exists and I believe it has also been shot down in court because the very first thing a JW elder does is report the crimes to Watchtower. Since he reports it, it is not confidential and the elder is not acting as a clergyman receiving confession, but rather as an interrogator and investigator (policeman) and a judge passing sentence.