Belligerence does absolutely nothing to help the situation. If detained, be cooperative, but non-committal, non-combative, and non-argumentative. Don't raise your voice, especially at the cops. Bottom line, he was being detained in the hopes that he's blow his cool and give the LEOs further reason to arrest him.
There's also a genuine duty and concern on the part of the LEOs about handing a firearm back to a hothead.
That said, if he was falsely arrested, he should sue the city for false arrest.
On the other hand, "I am not going in the back of a police car" is technically resisting arrest, even though later he complied. I find his continued belligerence, however, rather disturbing, as did the LEO's who took him in.
This is a classic example of how NOT to handle things. As for
his statement about "hoping for a public apology from the officers," I dare say if he's been "cooperative, but non-committal, non-combative, and non-argumentative," they'd have let him go in short order, as MOST CSPD officers are well aware of the few holes in their cheat sheets.
By the way, their "cheat sheet" runs into the hundreds of pages. It's called "General Orders," and yes, it's a condensation of local, state, and federal law. Even lawyers and judges aren't clear on the full nuances of the law, and many have their own "cheat sheets," compiled by their research staffs. Police Officers are held to very high standards, but their profession is enforcing the law, not arguing its finer points. General Orders are created both for law enforcement officers (sworn officers) on the streets as well as military officers and line troops. The latter is invariably created by the JAG (Judge Advocate General) staff - i.e. lawyers - within a theater of operation. It's designed with two goals in mind: Keep the troops out of harm's way, and to expediently prosecute the war.