As a preliminary matter, I think that this was absolutely bone-headed. Arresting this guy gives the term "farm animal stupid" new meaning.
That said, the mall is private property. As such, it is not subject to the First Amendment. In other words, unless the prohibition is based upon unlawful discrimination (race, gender, age, sexual orientation, handicap and, in some states, sexual preference), the owner can restrict access however it sees fit. For example, the owner could require formal wear on all patrons. Stupid, yes. Unlawful, no.
The owner was perfectly within its right to order the man off the premises because the order was not based on a prohibited category of discrimination.
In most states, the failure of a person to leave the premises after being ordered to do so by a person in control of the premises is a misdemeanor or a low key felony, depending on the state.
The troopers' analogy is unnecessary because you don't need to be in a house for the property to be private property.
The lawyer was ordered to leave private property. He failed to do so. The police asked him to leave and, when he refused, arrested him. Case closed.
If this had happened at a Federal Building, then I would be concerned. Since it happened on private property, I'm amused at my brother at the bar's stupidity and at the little lessons that life teaches.
