So your reaction to this story is to think that this incident shouldn't be used as an excuse to paint black people, particularly black men, as racist killers. That's correct and a totally fair reaction.
However, I doubt your first reaction to George Floyd's death was "This shouldn't be used as an excuse to paint cops, particularly white cops, as racist killers."
Everybody, regardless of ideology, interprets events through their ideological prism. Magnify stuff that fits your narrative, ignore/downplay stuff that doesn't. It seems like very few people, particularly on the internet/social media, are interested in looking at things from a balanced perspective, or looking at things in context.