Palfrey, Vitter, an Escort

In this article, it is suggested that Palfrey deliberately set up Vitter and one of her escorts who was working as his congressional aide. Yet later in the article, Palfrey claims she knew nothing of her clients other than first names or an alias.

Which idea is more credible? That she was Machiavellian enough to know who was calling and which of her escorts could be used against that person in the future? Or that she was like most agents and never bothered to screen?