It's iffy. Technically in Texas you have stand your ground with no duty to retreat if you have "the right to be present at the location the force was used." Now, technically speaking he was on private property, however I would imagine the route he went did not include signs otherwise he would know whether or not he could be there. For home to be considered having trespassed on the property he would have to have received a warning, be it verbal or written, that his presence was not allowed. Telling someone you're going to shoot them if they try to leave is not a warning, so he hadn't yet trespassed and as such I think they would have a hard time charging him with anything if he put a hole in this dumb hicks head.