Just finished the renewal stuff for my CHL, so I'm sorta "up" on Texas laws and such.
It doesn't matter if the gal was jumping up and down in the guy's yard and screaming all manner of insults: There's no physical threat, either apparent or real, and thus no justification for any use of deadly force.
You have been misinformed as to Texas law, Art.
"§ 9.42. DEADLY FORCE TO PROTECT PROPERTY. A person is justified in using deadly force against another to protect land or tangible, movable property: (1) if he would be justified in using force against the other under Section 9.41; and (2) when and to the degree he reasonably believes the deadly force is immediately necessary: (A) to prevent the other’s imminent commission of arson, burglary, robbery, aggravated robbery, theft during the nighttime, or criminal mischief during the nighttime; or (B) to prevent the other who is fleeing immediately after committing burglary, robbery, aggravated robbery, or theft during the nighttime from escaping with the property; and (3) he reasonably believes that:
(A) the land or property cannot be protected or recovered by any other means; or (B) the use of force other than deadly force to protect or recover the land or property would expose the actor or another to a substantial risk of death or serious bodily injury.
Acts 1973, 63rd Leg., p. 883, ch. 399, § 1, eff. Jan. 1, 1974.
Amended by Acts 1993, 73rd Leg., ch. 900, § 1.01, eff. Sept. 1, 1994."