The calamity that had befallen their neighbors evoked neither anger nor protest. The unperturbed ordinariness of their behavior captured for me the indifference of the bystander. To carry out the Final Solution, the Nazis needed the willful non-involvement of untold numbers of bystanders. The bystander is a person who feigns ignorance, indeed, acts contrary to what he knows by repressing his nobler instincts. The sequence of the verbs in this passage is critical.
Indifference is preceded by seeing.
We first see our neighbor's animal in distress and then pretend we didn't. Without that prior awareness, we would not be culpable. Our failure to comply with this biblical standard is hardly punishable in a court of law. The Torah's appeal is to conscience. The individual is both defendant and judge.