No one asked him to intervene. Period. Non-verbal doesn't count in a court of law. In fact, there were several passengers who asked Penny to let him go..which he didn't. And Peele died.
According to some of the other riders, he frequently yelled and screamed. But had never hurt anyone. If someone were acting erratically near me, I'd move or stand my ground. But until that person swung, I'd have no legal protection should I decide to pre-empt and attack him.
You are letting your emotions rule you.
Taking the law into your own hands is a dicey proposition
This ^ objective analysis [

] brought to you by the usual suspect.
What a hack Jerkoffwithnobrains always is.
The reality is this. The case is in NY. So unless the defense gets lucky with a lot of subway users (the strap-hangers), there is a decided liberal demographic tilt. It favors the prosecution in a case like this.
That’s a big strike against the defendant.
A possibly bigger strike is that in order to make use of the defense of “justification,” a defendant has to have perceived a genuine risk of imminent injury to himself or others. There is some confusion about what led him to feel the need to get involved. But it
will be a question at trial.
He certainly did NOT have to be invited in order to get involved: Jerkoffwithnobrains is simply wrong on that facet of his rant.
There is an even bigger problem with how
much force was used and for how long. Factually, given the tragic outcome of death, there is a viable prosecutorial argument to be made that the force
was excessive, almost by definition.
Nobody with any kind of real world experience should make predictions about how a case like this might turn out. But there are some good reasons for the poor defendant to feel worried.