I HAVE medical training and I dont always stop and help.
If its too dangerous for me to get out of my car and deliver aide, as in I run a high risk of getting hit because of poor lighting, the cars being in the middle of a busy highway, etc. then I drive by and call 911. I dont have a bright orange vest, big rigs and traffic cones to deter people from hitting me.
Ive been explicitedly begged by some family members to not stop at MVCs because of this:
http://warchild.blog-city.com/biketoberfest_deaths_sad_tragic_random.htm
The seminole county school teacher was my Aunt Karen. She got hit because she stopped to help and died.
I also dont stop for people laying in the street, grass, or sidewalk late at night, I drive by and call.
This person did his part, he may have not felt safe, there may have not been anything he could do.