He could have just straight up lied, or interpreted the question in a way favorable to him (I thought you meant millions, not less than $100k).
He cooperated at all points and was doing nothing wrong. The logical conclusion is that being truthful and cooperative is not going to keep you out of trouble.
> The lesson here is clear: do not cooperate with the police
Suddenly clamming up is a problem, doing so less suddenly is not (I'm elsewhere in this thread roughly advocating for clamming up about anything not directly related to the traffic stop)
https://www.oyez.org/cases/2012/12-246
I don’t see how telling the officer you have $87k is probable cause for a search, anyway.
First, it is not illegal to have a car or cash.
Second, in the US at least the government does recognize a limited right to privacy in the form of the 4th amendment which spies to States as well. An officer cannot search you, your car or your home without a warrant from a judge or a tangible reason to believe you are committing a crime.
Also, the police have a limited time to conduct the stop. Once they give you back your license, you can immediately leave regardless of what the officer requests that you do. The stop is over at that point, and they cannot legally detain you any longer.
That’s a very specific question. Did the officer already know the answer?
That reminds me of something I think I read. Is there are companies that specialize in identifying motorists that are carrying large amounts of cash. They make money by selling that info to the police.