I thought he said, "Why didn't you ask a priest?" because the priests knew that he was doing it, but they swept it under the rug to avoid scandal. The priests would deny that it was happening, but the nuns (with little authority) knew the truth.
I thought that too, for a moment - especially in light of the fact that we DO know the church covered up
many scandals. But, I guess, for me what was missing when Meryl kept talking about what the nun told her, was that he didn't have a
guilty resignation about it. It was more of an exasperated one. Like, "Oh, here we go again with the viscious rumors." There is a saying: You can't prove (or disprove) a negative. How was he supposed to prove nothing happened?
Maybe from his own childhood and upbringing, maybe coming from a broken home himself, he might have more of an affinity to helping little lost boys and taking them under his wing. But, it appears to be too much attention, and possibly the wrong kind of attention. Who knows?

To me, that's why there's doubt.
Back, 30 years ago, when I was a junior in high school, I was walking out the school's back door at the very same moment my vice-principal was leaving. I always liked him. We got along great. He was the cool v-principal.

He asked me if I wanted a ride home. I told him where I lived. (It was a couple miles away and not in his usual direction.)
He said, "That's fine, let's go."
I hesitated for a moment. He saw that and said, "Are you afraid?"
Fear hadn't even
entered my mind even though he was black and a big man. (The school was predominantly white. There was a lot more racism back them.) I truthfully said in shock, "No!!!

I was thinking: I have some heavy books upstairs in my locker. I'd love to take them home especially if I'm getting a ride, but I don't expect you to wait for me to go get them. You're halfway out the door."
He said, "No problem. Go get them, I'll wait."
"Really?" I ran upstairs, got the books and jumped into his car. He drove me directly home without any inappropriate occurence.
In today's times, if anyone saw a teen girl getting into the v-principal's car after school, there would be rumors.
He could also be in danger because what if
I reported later that he molested me, even if he hadn't.

An innocent intention and incident could really be blown up the wrong way by the wrong people.