All of this is very typical.
Once the CO was directly asked if a known pediphile came into the congregation could you warn others. The answer was absolutely not. The elders were to in a sense "babysit" the person. They had to make sure he never worked with young ones in field service and if they were getting friendly with a family to talk to him- NOT the family. The problem is you cannot watch a person 24 hours a day. The elders and their families would be protected but not the rest of the congregation.
They are more worried about protecting $ and reputation than in protecting the congregations.