I thought it was a very unfortunate situation and, reading between the lines, that General McChrystal (a fine officer) appeared to have been brought down by some dumb comments by staffers who had been drinking with a reporter and forgot to say "off the record." (Happens more often than you would think.) However, reading the article about this investigation, and drawing on experience as a veteran and a trial lawyer for many years, I was not blown away by the fact that in certain cases nobody admitted saying or hearing the most damaging comments. In and out of the military, when careers and livelihoods are at stake people will often say "I don't recall" or "I didn't say that" to get off the hook. It may be that the reporter made things up out of whole cloth, but it also may be that individuals who made the most damaging comments wouldn't admit it later. If I had to guess I bet they said things like "I don't recall that being said" -- any trial lawyer will tell you that the number 1 falsehood people tell under oath is "I don't recall X" (because it doesn't "feel" that bad to say it and/or it is terribly hard to disprove).
Again, I thought it was a sad situation, nor am I trying to pick a fight with those who found the Pentagon investigation and conclusions more convincing then I did. Perhaps I am just overly cynical.