You're right. If someone is being aggressive and shouting the n-word, it's probably best to not engage, in case they get violent. But, as a white woman, the vast majority of racist encounters I experience are jokes, flippant comments, or witnessing micro aggressions. You can absolutely call those things out, as they're happening. Unless, of course, you want to make excuses and not rock the boat and be tolerant of racism. I guess that's always an option. You do you.