When I told an elder what my dad had done to me as a child the elder looked straight at me and told me I was LYING!!!!!!!!!!!!!!!!!!! Then the whole elder body said I was mentally crazy
I am pretty sure he knew deep down that you were not lying, he must have seen something was wrong with your dad to have instinctively disliked him so much. But he probably couldn't admit that because that would mean that the organization is not the perfect spiritual paradise they say they are, and that you had been let down by Jehovah's appointed people.
To be fair, many men, especially of the older generation, are very uncomfortable with child sexual abuse, so they try to pretend it doesn't exist. It's no excuse, but JWs are not the only ones to struggle with this. They are just one of the few organizations that still pretends it's not a problem.