Not exactly. He answered some questions, but refused to answer THAT question. So, in court, it's legal to demonstrate that said question was unanswered, and the jury can assume what they want.
I'm guessing that he was guilty, and that tidbit wasn't what got him convicted. It only served as improper grounds for appeal.
That said, I'd say that if you're guilty, and taken into custody w/out an arrest, the only word you should utter is 'lawyer'.
To your personal situation w/cops pulling you over...I'm sure you know that they converse with you in order to discern sobriety, or the lack thereof. On those extremely rare occasions that I get pulled over on my way home from pool league, I LOVE telling them I'm coming from the bar....because I haven't had a drink.
Edit...oops...that wasn't you with the anecdote about being pulled over