I'm not quite sure how I feel about this. Impact can reveal underlying issues but is not necessarily racist in and of itself.
Consider the policy of "draw 100,000 names out of a hat and search those people for drugs". It is very unlikely that the demographic of those arrested as a result perfectly matches the demographic of the nation as a while, but I think it is hard to argue discrimination or prejudice here, because there is not even an opportunity for a human to have exercised discrimination.
Fishing stops like the OP posted try to be like this policy - a random dragnet. The issue, of course, is that the randomness is implemented by a racist police force. Black people are "randomly" stopped disproportionately, and treated harsher during the stop. So the disproportionate result is plausibly explained by racist intent.