Good thread, Bob. I don't know that serendipitous would be an accurate description, but it was loaded for me when I recalled it.
I believe it was the same summer the CSA had continued at the church camp where I was a counselor. Two of the perp's teenage sons were also counselors.
I came across one of them violently shaking an 8-10 year-old camper by the shoulders and yelling at him. The kid was absolutely terrified of this sloppy, fat bully, at least twice his size. I can still visualize the kid's eyes bulging. I don't know where it came from, but I told the bully to knock it off, immediately put a stop to it and the kid ran off.
Naturally the bully attempted to minimize the whole thing. I don't recall if I ever mentioned the incident to anyone. Probably not. Obviously at 16 I couldn't put it all together, but I believe that confronting the perp's son was my way at the moment to get back at the perp.
Today the son is a father and school teacher.
"The Answer to the Great Question Of Life, the Universe and Everything Is...Forty-two."