First, the "a" vs. "er" distinction is one that has been discussed, so I know none of you actually don't know the difference.
Even if it was phonetically the same word, you can't possibly not see any difference in a black rapper using the word endearingly and a white sorority girl saying QUOTE:
"I love how I act like I love black people because I FUCKING HATE N----RS. So that's really interesting, I fucking hate n----rs, but I just saved the fucking n----rs by shutting that water off"
And then double, triple, quadrupled down and in her non-apology video by angrily shouting "I don't care if it's Martin Luther King day, N----r N----r N----r!"
This isn't an issue of her forgetting to censor her self while doing Jay-Z at karaoke. Jesus...