I would never just randomly hold someone at gunpoint. The way the guy was acting made me quite nervous. The only time I would hold someone at gunpoint is if the acted hostile and I felt they were a threat to my well being. As for my local laws, Indiana law states the following. And seeing as I was basiclly a sitting duck in the tree if the guy was in some way hostile. I have every right to hold him for the authorities.

Firearms and self-defense. Specifies that a person: (1) is justified in using deadly force; and (2) does not have a duty to retreat; if the person reasonably believes that force is necessary to prevent serious bodily injury to the person or a third person or the commission of a forcible felony. Specifies that a person: (1) is justified in using reasonable force, including deadly force, against another person; and (2) does not have a duty to retreat; if the person reasonably believes that the force is necessary to prevent or terminate the other person's unlawful entry of or attack on the person's dwelling, curtilage, or occupied motor vehicle.