Legal Question in Traffic Law in California

That's an interesting question. It is a crime to surreptitiously record a conversation between two people that is thought to be private. Whether a conversation involving a public employee during a police stop is a "private" conversation is a matter that would need further research. Certainly, if the police officer knew that you were taping it, she wouldn't be able to claim that it was a private conversation. It might aggravate the situation, however, if you were to do so. Perhaps a criminal attorney could follow up with your question.