I am sure that the intimidation was ramping up.
He caved. While that was his choice, he could have asserted his rights. It might have ended up with him in lockup, but the settlement would have been better.
Too many people defer to the police, and they like it that way. The Police need to encounter informed citizens who know and defend their rights.
And always, always, ALWAYS video any police encounter. It helps keep the record straight.