Might Reuters have cropped it before posting it?
When the original photo is converted to a web formatted jpeg, it was probably reduced to 72 or 100 dpi, that would result in the stright line pixels if that portion of the image had been close to straight in the original photo.
Keep in mind that news photographs come from tens of thousands of people -- some directly employed by a media agency, but most simply free-lancers.
That Rueters published a bogus photo doesn't mean Rueters is in on some conspiracy. It just means (without knowing more) that it was sloppy on this one occasion and, probably, will never accept a photo from that photographer ever again.