Considering John Weaver, McCain's former chief strategist, is the only former McCain aide to have talked to the NYT on record, the swirling rumors are that he was one of the "associates" to give anecdotal evidence on McCain's and Iseman's relationship. Marc Ambinder, however, begs to differ:

This is highly unlikely.

First, the Times began to report the story before Weaver left the campaign.

Second, having had many conversations with Weaver before and after his break with McCain, it's clear to me that he retains enormous affection for his former boss; his primary emotion is one of sadness and not vindictiveness. I could be reading Weaver wrong, but I don't think I am.

Who knows, but I think if Weaver didn't want to be fingered as the source, then he would not have put himself in such a suspicious situation. Another thing to consider, "associates" is not aides. As Ambinder notes, if it were former aides, the NYT would have said "aides."