I know--speculation—and it may have been covered in comments elsewhere, but I can't help thinking that there was nothing accidental about the General's comments.
I recall Gen. McChrystal being pretty adamant that he could get results, provided he had enough resources. And while any General will always ask for more troops, the increased troop levels seemed to have satisfied his desire in terms of overall troop strength.
And yet, we still hear disturbing news from across Afghanistan. Things aren't going well. The Taliban are still able to take the initiative. Casualties increase.
That brings us to the latest article from Rolling Stone.
Unguarded moments or not, there is no way that the number and tone of comments that have caught attention as insubordinate could have been expected to remain off the record.
I think the General knew exactly what the consequences of his actions could be. And perhaps, it's a better way for him (from his perspective) to exit the stage. "Hey, I could have pulled it off, if they just would have left me alone..."
Better to be fired for insubordination than for losing, from a General's POV.