The freelance journalist who wrote the revealing article for Rolling Stone magazine on Gen. Stanley McChrystal is a little stunned that the piece brought down the top-ranking commander in Afghanistan.

In an interview with CTV, Michael Hastings says he expected fallout from the investigative piece, but not the end of McChrystal's posting.

"I thought Gen. McChrystal was essentially un-fireable, that his position in the administration and in the war was very secure," Hastings told CTV's Janis Mackey Frayer on Thursday, in Kabul.

"So I expected that for three or four days they'd have a rough political crisis but that he'd survive it."

Hastings' article, entitled "The Runaway General," presented McChrystal and his staff as outwardly mocking of members of the administration in Washington. The piece caused such a firestorm Tuesday that U.S. President Barack Obama was compelled to fire the general Wednesday.

The president said the remarks McChrystal made to Hastings did "not meet the standard that should be set by a commanding general."

Hastings says he is a little surprised by the furor, but hopes it draws attention to the disconnect between military leadership in Afghanistan and civilian leadership in Washington.

"For me, with the sort of media frenzy surrounding the story, what's most important is that it should draw attention to our Afghanistan policy and the fundamental flaws that are underneath it," Hastings said.

"I think it would be unfortunate if this was just looked at as a personnel change, as a sort of inside Washington gamesmanship. What I think the story is really about is how the (counterinsurgency) strategy is failing and how it's not going to work and Gen. McChrystal's life and what he's done over the past year is just the vehicle to tell this larger story."

Hastings said he knew pretty early on in his month amongst McChrystal and his staff that he was gathering good material for his article.

"But I also know that in Afghanistan, often things that your think are going to get a lot of attention don't get a lot of attention at all, and then other things that you don't think will get a lot of attention, for whatever reason, they happen to catch at the right moment," he said.

"But I did not necessarily know what I was going to write until I sat down for 48 hours and banged out the first draft."

The journalist added that there was a lot of information McChrystal told him that he couldn't use, because the comments were made off the record. Plenty of other statements "of interest" were made on the record, Hastings said, but he couldn't fit them all into the Rolling Stone piece, because of a lack of space.

It was a bit of serendipity that allowed Hastings to have as much access as he did to the general. The journalist had been scheduled to interview the general in Paris, fly with him to Kabul and then follow him around Afghanistan a bit. But the volcanic eruption in Iceland grounded planes in much of Europe, delaying McChrystal and his entourage in Paris and forcing them to take a bus to Berlin. That allowed Hastings to mingle with the general and his staff for close to a month.

Hastings says he was a little stunned by how much access to the general he received, but says he knew within the first day that this interview was going to be unique.

"The first few conversations I had with him were unusually candid, and they continued for the whole month that I spent with him," he said.

"Within the first 24 hours I was there doing the story, (McChrystal) started making jokes about Vice President Biden. That was the most surprising moment that I had. And then secondly, later that night, when they all became extremely intoxicated and sang songs about Afghanistan, that was also surprising."

McChrystal's ouster as the head of NATO forces in Afghanistan has led to his being replaced by Gen. David Petraeus.

Canada's Chief of the Defence Staff, Gen. Walt Natynczyk is a personal friend of Petraeus and calls him a "soldier's soldier." He says he has served with Petraeus a number of times and Canadian operations will continue without issue throughout the transition.

Defence Minister Peter MacKay says Petraeus has a wealth of experience and the change in leadership will not affect Canadian military personnel.

The change in command occurs as NATO forces prepare for a major military operation in the Kandahar area this summer.