your wife had to suffer a bit from the effects of the police state we are finding. I offer two things to consider, which may console you both. First, the police state will end when the dollar crashes. This is because the government money now funding all these agents (including local cops) will end. Of course, a concern is that the powers that be attempt martial law then, in which case all bets are off and a civil war may ensue, but either way, the police state won't simply grow unchecked. Second, even before the dollar crashes the police state may start waning, because again govt. financing is being challenged (see current fiscal fight in Washington).
I say that because your situation doesn't look good for retaliation IMO, now after the fact. You will likely spend 95% time and energy to get less than 1% of whatever you might consider victory. And in all likelihood the officer(s) involved won't change behavior one bit as a result.
The problem is your wife basically brought a slingshot and toothpicks to a sword fight.
You have to understand cops do their job EVERY DAY. They know what they can get away with, and how to handle various forms of resistance. As a citizen, yes, we as individuals are powerful, but only when we know EXACTLY which weapons we have and how to use them.
Losing examples: "I don't think the law requires me to" "I don't want to" "I don't consent to this..."
It's no wonder the cops didn't blink. They knew the person they were dealing with had no idea of what EXACTLY the cops could do and what they might be fearful of reproach for. Hence they proceeded to handle the situation as they saw fit. And if their actions are questioned later they will simply say "suspicious behavior" for justification of their probable cause. Next case.
Sorry, not trying to be unsympathetic, I am, but that's how I see it.
EDIT: to clarify, what your wife SHOULD have done (and known) is specific rights. Instead of "I don't think" or "I don't want" it has to be "the law is such and such (or there is no law)" and "I don't HAVE to, officer". The latter tells the cop you are aware of the situation and how much potential trouble you might cause them for violating your rights.