You're normalizing to raw population. You want to normalize to "armed conflicts with the police" or similar.
Using the above FBI 2018 homicide statistics, blacks committed 3177 homicides in 2018, while whites committed 3011---in other words, blacks account for ~50%, despite only being 13% of the population.
Taking that proportion as a rough "criminality index," and multiply 53.5 by 13/50, and things look very different.
The whole point of the comment you are questioning is to also normalize it to something besides total percent of population. The new comparison seems to say that if you are a violent criminal your chances of getting shot by the police are higher if you are white.