The thread was titled "Explicit racism". There's no ambiguity there."Racist incident" sounds a lot like how someone who doesn't speak English natively might say "incidence of racism" but I'll keep my mind open both ways. Where in the OP was that edited out from?
Edit: The title was slightly longer, like "Explicit racism in a game" or something along those lines, but we can all agree that the important bit is "Explicit racism".