security experts say it takes training "not to act"
This is a really great point.
Apparently he just stood there and cracked open a beer.
When he didn't respond properly to a verbal intervention to pay, etc., the next step is to just call the cops.
No matter how pissed off you are, never go for the bait of some kind of physical action - this creates the opening for them to attack, which they are primed to do anyway.
If they are going to assault you - make them climb that hill to close the space between the two of you, and by doing so open themselves up to your counter-strike.
You cannot allow them to be within striking distance of you at the start - ever.
In Japanese budo this distance is called ma-ai, and is as basic as it gets.
Hotheads (like myself) really have to be consciously disciplined about this.