This appears to me to be a flagrant misuse of anonymous sources.  Credit The Post for not trying to make a lame excuse as to why it allowed anonymous McChrystal aides to impugn the integrity of Michael Hastings, who wrote the notorious article that led to the general losing his command and probably his career.  But the fact that the Post allowed anonymous sources to attack Hastings and his editors is unconscionable:

[O]fficials close to McChrystal began trying to salvage his reputation by asserting that the author, Michael Hastings, quoted the general and his staff in conversations that he was allowed to witness but not report.

A senior military official insisted that "many of the sessions were off-the-record and intended to give [Hastings] a sense" of how the team operated. The command’s own review of events, said the official, who was unwilling to speak on the record, found "no evidence to suggest" that any of the "salacious political quotes" in the article were made in situations in which ground rules permitted Hastings to use the material in his story.

A member of McChrystal’s team who was present for a celebration of McChrystal’s 33rd wedding anniversary at a Paris bar said it was "clearly off the record." Aides "made it very clear to Michael: ‘This is private time. These are guys who don’t get to see their wives a lot. This is us together. If you stay, you have to understand this is off the record,’ " according to this source. In the story, the team members are portrayed as drinking heavily.

Officials also questioned Rolling Stone’s fact-checking process, as described by [Rolling Stone executive editor Eric] Bates in an interview this week with Politico. "We ran everything by them in a fact-checking process as we always do," Bates said. "They had a sense of what was coming, and it was all on the record, and they spent a lot of time with our reporter, so I think they knew that they had said it."

These anonymous sources even provided copies of emails between a Rolling Stone fact-checker and McChrystal media aide. 

In my view, there is no reason for this article at all except to allow anonymous allies of the general to strike back—without bearing any responsibility for their attacks.  It’s as if the newspaper said, “We’ll do your dirty work for you.”

That The Post  allowed this reinforces the point Politico made in an earlier post subsequently scrubbed of the inside baseball admission.  The point was an admission that what made Hastings’ story so dramatic was that usually reporters hold back things they hear that might destroy their relationship with the institutions they cover.  In other words, we can’t trust what the Post  or other newspapers tell us because reporters and editors don’t want to upset their cozy relationship with the people they cover.