First, Ken White's point was that she was likely basing her conclusion on information she learned as part of her representation of the guy, which would be privileged. This gets into personal preference, I think. I wouldn't outright ask someone, since that's asking to be lied to (and clients lie enough as it is). But if I'm doing my due diligence in investigating the matter, I'd probably have a pretty good idea. I doubt it, even there. I've done very little criminal defense work in my career, but I (and others more experienced) would actively dread getting a truly innocent client. Those are the ones that keep you up at night, because what if you screw up and an innocent person goes to jail? But I think this varies from person to person.but would you as a lawyer actually ask your client if they did the things of which they're accused?
I think especially in a child rape case you wouldn't want to know, because even that knowledge might adversely affect your ability to provide a vigorous defense.