That goes with what I've learned over the years... no one knows exactly what they're capable of doing or NOT doing until it happens. No one knows what they will do (or not do) in any given moment.My sympathy and condolences to the family of the child.
The perpetrator was a virus, who ability to infect others has been eliminated.
As far as the bystanders, it depends on who they were and what their abilities were; as with many other issues, we who were not there can second-guess the situation all we want - but when it comes down to it, we weren't there. Would I hope that in a similar situation, I would jump in? Certainly - and sitting here safely, at my dining room table in front of my laptop, I say to myself that I would - but unless and until each of us is in such a situation, we cannot say with certainty just how we would act. The people who did not intervene will have to live with that the rest of their lives; that may not be enough - but it's what will be.
As you said we can arm-chair this to death but when it really happens right in front of us... :idunno: who knows?
But our hearts, in this moment are definitely in the right place.