These kind of incidents are far from rare; though admittedly those that actually get media attention turn out to have a disproportionately high rate of falsehood. (Not usually of the "it never happened" kind, but of the "they did it themself" kind.)
It happened to my family a few years ago, and we live in New York City, not exactly the Deep South. They just spray painted the n-word all over the place, including the fence.
A news crew just so happened to be in the area because either a murder or robbery happened nearby, I forget. They asked if wed be okay with an interview and an interview was had.
My dad never painted over it, never felt like it and it didnt bother him. Said if they want to be stupid, let the symbol of their stupidity stay out there loud and proud. Eventually one day he woke up to it gone. Itd be funny if it was the same vandals who somehow had a change of heart.
Oh for sure, I'm not saying they're always false. But also - notice his reaction, compared to those of the ones in the stories that tend to go viral, where they're generally ranting to no end and often set up a GoFundMe or similar a few days later. ---
Proud to be part of the 1% of society that's smart enough to realise Australia is not real.