I look at it like this, even if these individual witnesses were familiar with the case you speak of "their" opinion would only be in line with the official "company" line for eg
"These are isolated cases. JWs abhor child abuse. There is worse abuse in other religions. Now go away opposer."
Individual witnesse have no power within the group to change the group and that's especially so with sisters. They are discouraged under threat of De eFFing to avoid all negative media reports and not to believe them if they do come across one. They are not the ones who make policy or change policy. They have zero power to affect change except to leave if they don't like it and possibly including all their social connections.
So they close their eyes and ears to any cognitive dissonance creating flaws and contradictions.
Talking to them is like complaining to a shop assistant about store policy the assistant will not want to complain about their employer in public even if they agree with you. There is nothing they can do about store policy even if the policy is unfair. They have no power. There is some saying about "...not taking a no from someone who doesn't have the power to say yes..." or something like that the meaning being you need to go over that person's head to get anywhere but applicable to dealing JWs.
I'm not saying it's a waste of time approaching cart people but I just wonder considering the brick walls they throw up what the goal should be when approaching cart people?