This is a very interesting article.
Man charged with killing Burleson County Deputy No Billed by Grand Jury
In short, the agency did a "No Knock" entry on his trailer. The man responded by opening fire with his legally owned firearm. Mr. McGee's argument was that he was protecting the life of his pregnant girlfriend, and the jury bought that argument.
Please note that the Felony drug charges against Mr. MaGee have proceeded forward, so the man is neither scott free nor clean in my book.
There have been a small handful of self defense arguments where raids end badly for Law Enforcement and turn up no evidence. With this court decision, I wonder if these arguments will end up at the Supreme Court.