I'd be inclined to think that if there had been an article in Newswek saying that a US Government internal investigation has determined that this desecration of the Qu'aran did not occur it would have been just as likely to spark off riots.

The point is, the allegations had been reported widely, and are probably seen by most people around the world as pretty plausible, in the light of the recent record of the USA when it comes to the way prisoners are treated.