Interpreter's ethics/Ethische Frage für Dolmetscher

I just traced the translator ethics article to its original source at the New York Times, where it costs something to access. While at that site, I found another ethics question about an interpreter:

Some time ago I was working as a court interpreter, translating what is said in court for the defendant and what the defendant says for the court. During a recess, the defendant confided that he did commit the crime and intended to take the stand and lie about it. I sought the advice of a colleague, who then informed the judge. As a result, I was chastised and lost my job. Was I wrong to divulge this information? E.N., Seattle

Of course, this kind of question is more commonly discussed when you're learning to interpret than the diary question is when you're learning to translate. That's partly because defendants may have a completely wrong idea of the interpreter's role and not realize it is impartial.