When it happened to me by an elder, the reason I didn't take it to the elders right away was because I didn't understand what was being done to me was wrong. I was completely uneducated sexually. I felt like if an elder was doing this to me it must not be wrong. It's twisted, I know, but it's what I felt as a child.
Additionally there is the fear factor, too. Like what if they don't believe me, or what if they think it's all my fault. There may be a lot of reasons why it took him so long to come forward.
I sure hope he gets the help he needs.