Here's DSP misspeaking negative as nigger which caused him to get banned almost immediately.
Oh nooo but it doesn't meet your exact specification of nigger over VoIP so I guess it doesn't count. As though it makes any sense that Twitch would let that slide but then ban a relatively well known streamer like DSP for just fumbling his words like a dumbass.
As a bonus here's a nigger over CS VoIP moment where the streamer literally screams like an autistic child to drown out the nigger words
https://kiwifarms.st/threads/soyjak-party-the-sharty.145349/post-15715201
The guy probably didn't get banned as he used the Twitch approved method of screaming incoherently, but the fact that this is their reaction is all you need to know about the state of Twitch moderation and the nigger word. The Christmas clip I mentioned earlier is also 2 posts down from that one and worth a watch.