Nobody involved believes Daniel Penny intended to murder anyone.
Except perhaps you. Perhaps read the full op before posting spin.
Daniel Penny tried to control the situation. Marines are not trained to control situations. They receive an entirely different type of training. The outcome is sad, but lets not ignore what the dead man said:
"big life sentence"
"it doesn’t even matter if I died"
To a reasonable person, that sounds like the prelude to an act of mass violence. Mass shooting. Etc. They happen every day in this country. Daniel Penny is in a NY subway car, most people are not going to flee effectively. Daniel Penny is likely one of those unable to flee effectively. With the information presented to him, the least bad choice is to engage and neutralize the threat to everyone on the subway car, as he was trained.
I am no legal expert, but based off of that, I question if their is a jury of New York subway riders that are going to be found that are going to convict Daniel Penny of anything.