Whether intentional or not, she has done him as big a favor as he can hope for under the circumstances.
This begs the question:
If Corey and the government did Zimmerman a favor, what happens if the jury is stacked with black racist, like what happened in the OJ trial, but he is found guilty here?
Is this the kind of government favor you're talking about?
It's when the feds are running the show that the juries get stacked.