I try to be as objective on this as possible. I beleave in a society, where unacceptable behaviour is not ignored, but to be found a way to treat it. I would not want to comment on a racist post, since it would rather amlify it instead of smaller its vierwebase.
Someone in the train saiing something similar, I wouldmalso hold accountable for. Since I think to say nothing on bullying is accepting it. Accepting it is letting people fall, which get bullied. With this I do not agree. I try to defend minorities, which get bullied. Here I decided reporting it is the best way.
I am open to hear feedback how you react on racist expressions.