It would seem that you are correct.
I have to disagree. Electing to testify is offering yourself up to be crucified.
Did you see Dusek when he attacked one of the bug guys? He was yelling "D...N....A" with veins sticking out on his neck. It was brutal, not to mention unjustified. Westerfield would probably have been treated as a hostile witness, and it would have been really ugly.
Dusek would have been like:
"Did you get off on it? Did you feel like a big man when you ripped her tiny genitals to shreds?!?!?! Did she beg you for her life?!!? Did you kill her before or after you raped her? Like the men in those videos... cruel... sick... merciless... EVIL... pounding ... pounding ---POUNDING ---POUNDING THE INNOCENCE OUT OF THAT SWEET CHILD'S SOUL!!! MY PSYCHIC ROPE OF TRUTH WILL HANG YOU BY THE NECK YOU MONSTER!!!"
You get the picture.
Being "too cooperative" is what got him into this in the first place.
If that prosecutor attacked me the way you stated, I'd look right at the judge and say this, "Your honor, I'm more than willing to cooperate and aid in discovery to the best of my ability. I will not sit here and have this individual prejudice the jury in this manner."
What's the judge going to do, hold you in contempt? LOL, if it's contempt or the gas chamber, I'll risk contempt and calling the idiot on his prejudicial behavior.