I was once told by a highly accomplished photographer that if you need to remove parts of an image afterwards, you may as well have retaken it. While this may be true in some instances, documentary is not one of them.
As I have said on my main site, the whole point of documentary is to tell a story. To retake an image would be impossible, however, to crop an image is to make the story stand out more. To illustrate this point I have chosen an image I took recently while having a coffee at St Pancras Station.
At the point of capturing the image, only I knew why I had taken. Some of you, having looked at it now, may have worked it out however, overall the image is too cluttered and too confusing. In my opinion, not cropping it would detract from the point entirely.