Sorry, John. I hadn't realized that was your point. Having watched only excerpts, I wasn't aware that the defense attorneys had tried to engage in name-calling, etc. That is not necessarily a sign of a bad attorney (although I don't know in this specific case). Lawyers will use the preliminary examination and other public statements as an opportunity to fire warning shots over the bow. It can be a way of telling a witness that "if that's goinna be your story at trial, prepare for a hellish few days of cross examination because we all know that's not what really happened and we're going to make you regret your pack of lies." Of course, they don't actually say that (they would if they could, but it could constitute witness intimidation), but that's the fear they hope to instill. If the witnesses start backing down from their sanitized stories, the prosecutor will be more likely to consider a more favorable plea deal. Also, we all know that witnesses sometimes change their testimony at trial - for whatever reasons (supposedly better memory, "I need to clarify that," or the question is asked in a different fashion). The defense lawyer hopes to lay the groundwork for all of that as early as possible, and the preliminary exam is often the earliest opportunity.