You guys are correct, and I'm probably being a little obtuse. I think we can agree he knew the significance of the policewoman's gestures, and understood her intentions.

I presume you were not there.

I was not there.

I do not know the reason for the "stop", or if there was in fact a stop.

When dealing with law enforcement, the conservative approach is to follow instructions. It is not prudent to "press to test" because you may be doing it all the way to jail.

That all makes perfect sense. I'm not so much talking about how weird his conduct is, as much as saying I'm baffled by the actions of the policeman and woman. The article says:

"...The two officers approached the suspect and he gave them a fake name. After learning the pilot was Gryder, the officers attempted to issue him six citations, police said... However, Gryder refused to sign the tickets and boarded his plane, a 1937 DC-3A... He started the engine and told one of the officers that if she moved, he would strike her car, police said.
The officer, who was standing next to the prop, moved out of the way and summoned backup..."

So they have spoken to the pilot, and attempted to issue the citations, THEN they let him board his aircraft. Then the engine is started, and he tells them that they will be struck if they move. Maybe it's a threat, maybe it's a statement of fact considering where they chose to park their car. I have no idea who's right and wrong, but I can't shake the impression that these cops were as smart in front of a DC-3 as a chicken is in front of a typewriter. They let the guy get away, and now they're all befuddled, next to a running DC-3 engine.

So now what? They use their aircraft stopping training? The pilot refers to the "police" section of the AIM? Seems like a ridiculous situation to me, and it's hard to tell who engineered it. So I just can't decide conclusively whether we're reading an article about a single idiot, or several, but I'm guessing the plural fits better than the singular.

The Police, when they arrived, pulled their cars back so the pilot could taxi clear of the runway to his spot and shut down.

Unlike cars, you don't just stop a DC3 and set the parking brake, then go to jail for 48 hours without the DC3 getting in a lot of people's way, or just rolling away. Remember this occurred while what remained of a tropical storm was blowing through South Atlanta.

It is reasonable to expect a pilot would be thinking about shutting down and securing the airplane as required and also reasonable to expect a Police officer to not understand the difference between a DC3 and a truck, or car.