I don't know if the couple parked on the homeowner's property or not. The available reports are not at all clear on that issue. If they did park on his property, then the homeowner may be able to beat the charge either under a claim of self-defense or pursuant to TPC §9.04 Threats as Force. If he does, he will have spent a lot of money to be victorious. If the car was on an easement or otherwise not on the homeowner's property, then his chances of winning are slim. Either way, I bet he wishes he could do this all over again.
This case is a great example why I end every CHL class with the same admonition -- "Be responsible, not merely legal." As a trial lawyer, I promise you you don't want your attorney to have to explain to a jury why you walked up to an alleged trespasser, ordered them off your property, then pulled a gun on them when they tried to explain why they were there. Add this to the mix - the woman had just lost her brother in a fiery plane crash. Some will argue that this is irrelevant, but I beg to differ. I've won a lot of cases by what I was able to put into the hearts of jurors. And don't think for one second jurors don't ignore the instructions and definitions contained court's "charge." If a jury decides you are a jerk, they're going to find a way to let you know how they feel.
Chas.