In The Dark Knight, when Batman interrupts (what would probably have ended in) Dent killing Thomas Schiff, Batman tells Dent that if people saw him doing this, then all of the criminals he'd locked up would be released. Now, I'm not a lawyer or even a student of the law, but it seems to me that the post-facto actions of counsel would have no bearing on a verdict rendered.
Is there some legal precedent of which I'm ignorant that the filmmakers might have been drawing from?
BATMAN : You're the symbol of hope that I could never be. Your stand against organized crime is the first legitimate ray of light in Gotham for decades. If anyone saw this, everything would be undone-all the criminals you got off the streets would be released. And Jim Gordon will have died for nothing.