Gibb, could the "logic" have had something to do with the belief that Black people are childlike and incapable of looking after themselves, which, as you know, was a common justification for slavery. I was thinking it might have a religious element to it as well because Berlin was a Belarusian (or Russian) immigrant from a religious Jewish family. The "fact" that the boy in the closet is, well, a boy might (if the rumour reflects religious prejudice) might be intended to portray Berlin as a child exploiter, like the old fence Fagin in Oliver Twist.

That's just my opinion though.