Lets take a close look at those photos. The link you give us is very careful not to show the original while talking about how they were doctored.
Judge for yourselves.

Not the difference that they were trying to make out it was. The report you linked to wants the viewer to form the impression that all the black smoke was digitally added and that there wasn't smoke rising all over the city. But the original picture clearly shows that there was a lot of smoke.
Furthermore it's worth pointing out that Reuters have removed every single picture by Adnan Hajj from there database and said that they are not accepting any further pictures from him. Oddly enough that isn't mentioned in the report.
Oh, I fully agree that the change in "amount of smoke" is not the drastic difference it may be understood by some to be. But that's not the issue here. The issue is the alterations, period - regardless of how drasticly they change the reader's mind. Obviously, Reuters is trying to react responsibly to this thing, but since any 7-year-old could see that that photo was doctored, the question it raises in my mind is of the quality (or lack thereof) of Reuters or AP's "quality control", as it were.
While the damage done with the smoke alteration is not very dramatic at all, what about that lady supposedly grieving over the destruction of her home - at two points in time separated by two weeks? Something like that definitely has potential to affect the viewer's opinion.
My point is this (pardon the cliche, but there's a reason cliches are oft repeated - they have a point). If news agencies cannot be trustworthy in small things, how can you trust them in large things?
In response to Rachel Corrie's death, I will just say that I worked with and alongside (literally) D9's in my army service, and soldiers were always reminded about the dangers of getting close to one in operation, since the operator has terrible visibility. IIRC, there have been Israeli soldiers who have been accidentally run over by D9's after getting too close.
I'm not saying that Rachel Corrie's death was ok since it was an accident. I'm simply saying that I do not believe it to have been intentional in any way, shape, or form.