The shooter committed a murder. Not manslaughter or something else. When you intentionally cause the death of an individual, it is murder under TPC Ch 19.
The question is whether the murder is justified under chapter 9 TPC.
A person may be able to use force or deadly force to protect themselves, another person, or property.
You really need to analyze the facts chronologically.
Some facts we don’t know, like whether the deceased was a trespasser. Did he have notice that his entry was forbidden, or receive notice and fail to depart?
It is important to note that The shooter producing a weapon is force, not deadly force, per TPC Ch 9.
He can probably use force to terminate a trespass. So the production of a weapon is probably legal. But the shooter just didn’t produce the weapon.
Discharging the firearm in the ground is deadly force, an aggravated assault, and also the crime of disorderly conduct - discharge firearm. I don’t see any justification for that at the moment it occurred.
This is significant for a couple reasons. One, if you are engaged in criminal activity, you lose the castle doctrine presumption and no duty to retreat instruction that you might have in a self defense case. Similarly, provocation, by firing into the ground by the deceased, causes the same legal consequences. Moreover, I don’t think this is a castle doctrine case anyway as element one of the defense is missing (attempt to enter or remove from occupied habitation, business or vehicle).
So the shooter is going to have a jury decide his case without the benefit of the most favorable parts of the law regarding defensive use of force. And the jury can consider whether the failure to retreat was unreasonable. Basically straight up old school self defense law.
Back to the chronology of the events. The production of a weapon is probably legal to terminate a trespass on land. The discharge of the firearm appears to be an unjustified aggravated assault. At that point the deceased, not the shooter, has a right of self defense. Grabbing or attempting to grab a firearm pointed at him seems like reasonable use of force in self defense, regardless of whether the deceased is guilty of provocation or not being in a place where he had a right to be or engaged in criminal trespass if that is found to be the case. It is still reasonable force if he is the victim of an unjustified aggravated assault.
Keep in mind the STATE has to prove BEYOND A REASONABLE DOUBT that the use of force, or deadly force, to protect persons or property was NOT justified under Ch 9 TPC. It is not the defendants burden to prove his use of force was justified.
I think the shooter has an uphill battle. The video makes him appear to be the first person who used force that was not justified.