I think it is a fair resolution. I have been to many train stops in large cities and they attract some really bad people, bums, and thugs. They usually all carry weapons. These are not easy patrol areas. Not an excuse but I can see where you can be on edge at these areas and make a knee jerk mistake.
The guy was on the ground and hand-cuffed and then was murdered.
Johannes Mesehrle killed a civilian who was in custody. It may or may not have been an accident. He got involuntary manslaughter with only 2-4 years.
Meserhle was a cop. Frederick was not. Exactly how is that fair?