If there was nothing I could do, then yes I would take the photo. More importantly I would publish the photo. The conversation of safety is being brought up again in part because of the photo.

The photo in this book springs to mind

http://bhs.cc/journalism/pdf/Chapter10Ethics.pdf

After it was published there were fewer incidents

Also, before criticizing the man, keep in mind the bystander effect. In most situations people don't do anything because they believe someone else will.