No, not that he necessarily needed her help to keep his perspective, but I wonder if, knowing she would react this way, (or so he said), he allowed Miss B to "entertain herself" with (albeit cruel) teasing, as a way to dismiss what he may have begun to feel about Lizzy. Does that make sense? Of course, if he truly felt regard for Lizzy at that point, he would not have let Miss B tear her down like that. But it would fit with his initially prideful behavior in Hertfordshire. Just wondering--not making a definite statement of opinion.

Regardless, you are right--Miss Bingley's brand of teasing was nothing like Lizzy's, as Mr. Darcy would come to know. Miss B's was pointed, ugly criticism of Lizzy and her family, and only added to the chasm of difference between the two women, I totally agree!

Actually, I think one of your ideas fits better--it's more plausible that he was letting Miss B know that he did take notice of other women--even in Herfordshire.

Thanks for letting me attempt to explain! :-)