First this is the NC law and only applies to NC. Second, with 3 against one odds I don't know since they had no visible weapon and made no threats.
(b) The lawful occupant of a home, motor vehicle, or workplace is presumed to have held
a reasonable fear of imminent death or serious bodily harm to himself or herself or another when using defensive force that is intended or likely to cause death or serious bodily harm to another if
both of the following apply:
(1) The person against whom the defensive force was used was in the process of
unlawfully and forcefully entering, or had unlawfully and forcibly entered, a home, motor vehicle, or workplace, or if that person had removed or was attempting to remove another against that person's will from the home, motor vehicle, or workplace.
(2) The person who uses defensive force knew or had reason to believe that an unlawful and forcible entry or unlawful and forcible act was occurring or had occurred.
(d) A person who unlawfully and by force enters or attempts to enter a person's home, motor vehicle, or workplace is presumed to be doing so with the intent to commit an unlawful act involving force or violence.
(e) A person who uses force as permitted by this section is justified in using such force and is immune from civil or criminal liability for the use of such force, unless the person against whom force was used is a law enforcement officer or bail bondsman who was lawfully acting in the performance of his or her official duties and the officer or bail bondsman identified himself or herself in accordance with any applicable law or the person using force knew or reasonably should have known that the person was a law enforcement officer or bail bondsman in the lawful performance of his or her official duties.
The CCL instructor said that means if you wake up at 3AM, you do not have to see a weapon and you may open fire. This applies to home, work, or vehicle.
That said, if somebody simply trespasses onto your front yard, you should not open fire without more threat. Tell them they are trespassing and they need to leave now. Also, you may NOT shoot to simply stop them from robbing you. If they are stealing your car, that does NOT justify using deadly force. But if they yank your car door open at a stop light, you should defend yourself. You can see there are grey areas.
As I understand it. if one had opened fire when they yanked the door open, that could be considered a justifiable threat. If they reached for the iPad and started to leave, it is not justifiable to open fire.