Yes. It's important to remember that guilty defendants aren't the same thing as convicted defendants. A rational decision-maker using Bayes' theorem wouldn't necessarily put all that much weight on the decisions of past juries, knowing as we do that they're not using Bayes' theorem at all. And, of course, a Bayesian would need exactly the same amount of evidence to convict a black defendant as they did a white defendant. That question is whether skin colour counts as evidence.