All the points you raised are irrelevant as far as a trespassing complaint goes.
This is from a more detailed account (LINK) from a different source:
Bell’s original arrest for trespass was later changed to a disorderly conduct charge. The Court ruled that Bell’s arrest was “unlawful” and accepted her lawyer’s arguments that she had a right to momentarily go limp to passively resist her arrest. The Court also ruled that because Bell was arrested on public and not private property, the city’s arrest charge was lacking.“The City has failed to show that Bell obstructed access to the Civic Center, and we find there was insufficient evidence to support the charged offense” of trespassing, according to the Court’s 18-page ruling. “Bell reasonably resisted officers during an unlawful arrest for the City’s unsupported trespass charge.”
“This is an important victory for the rights of Catholics in America, faced with a rising tide of anti-Catholic hatred, in this case officially sanctioned by the City of Oklahoma City,” Christopher A. Ferrara, the president and chief counsel of the American Catholic Lawyers Association, said in a statement. “ACLA attorneys are now reviewing the options, including a federal civil rights lawsuit on Mrs. Bell’s behalf. The gross violation of civil and constitutional rights in this case must never happen again in Oklahoma City.”
Except the first point, which is that it was public property. The arrest was determined to have been invalid based on that alone.