It wouldn't be the first time.
Well, technically, the prosecution could decide not to release
any of witness 9's statements. All that would do is preclude them from calling her as a witness.
And she's pretty useless as a witness in the murder case, even in rebuttal. I agree that it is legal to release all the testimony
if the prosecution is considering calling her as a witness for any purpose. My problem is with even considering having her testify. She can't testify about the allegations, even if she testifies.
So I'll back off the insinuation that it might have been prosecutorial misconduct to include the statement, though it would be misconduct if the witness was coached to say she remembered Zimmerman supposedly not liking black people. Impossible to prove, but improper coaching is very common, and the statement about Zimmerman not liking black people seems awfully convenient given that it's totally unrelated to the allegations and also inconsistent with the FBI's findings and several well-sourced anecdotes about Zimmerman's behavior. I do not claim it was
illegal to include witness 9's statements, just that it looks like a dirty trick to smear Zimmerman, and an act of desperation.