delete my account? The guy pointed a gun at him that's more than enough. If the guy ran away and he shot him in the back or if he executed him on the ground I could see how a jury would definitely do something like that. Several parts of your own states self defense law back him up.
a person is justified in using force against another when and to the degree the actor reasonably believes the force is immediately necessary to protect the actor against the other's use or attempted use of unlawful force. The actor's belief that the force was immediately necessary as described by this subsection is presumed to be reasonable if the actor: - See more at: http://codes.lp.findlaw.com/txstatutes/PE/2/9/C/9.31#sthash.1Ll0Hzbi.dpuf (B) unlawfully and with force removed, or was attempting to remove unlawfully and with force, the actor from the actor's habitation, vehicle, or place of business or employment; or - See more at: http://codes.lp.findlaw.com/txstatutes/PE/2/9/C/9.31#sthash.1Ll0Hzbi.dpuf
Doesn't fall under any of these categories where force is not permitted
(b) The use of force against another is not justified: (1) in response to verbal provocation alone; (2) to resist an arrest or search that the actor knows is being made by a peace officer, or by a person acting in a peace officer's presence and at his direction, even though the arrest or search is unlawful, unless the resistance is justified under Subsection (c); (3) if the actor consented to the exact force used or attempted by the other; (4) if the actor provoked the other's use or attempted use of unlawful force, unless: (A) the actor abandons the encounter, or clearly communicates to the other his intent to do so reasonably believing he cannot safely abandon the encounter; and (B) the other nevertheless continues or attempts to use unlawful force against the actor; or (5) if the actor sought an explanation from or discussion with the other person concerning the actor's differences with the other person while the actor was: (A) carrying a weapon in violation of Section 46.02; or (B) possessing or transporting a weapon in violation of Section 46.05. - See more at: http://codes.lp.findlaw.com/txstatutes/PE/2/9/C/9.31#sthash.1Ll0Hzbi.dpuf
The guy didn't want him to call the cops because he knew he was going to go to jail so he wanted to stop him.