I can’t compare a uniform officer giving legal commands of compliance to an individual who then decided to attack the officer to a bunch of vigilante wanna be fake cops doing everything wrong and illegal. Sorry, do dice on that.
The only way way McMichaels can claim self defense is if Arbery was the aggressor/initiator, but that isn’t the case here.
Of course McMichaels is going to create a defense, that is their right to do so. They can try to present as much legal evidence they can. In some cases past violations of the victim can’t be evidence because it would be irrelevant. McMichaels are not uniform police officers, the shooter has zero law enforcement experience but he took it upon himself to play cop. He is responsible, he put Arvery in that situation and McMichaels had zero experience on how to control that situation. That is why police work should be left to the police, not vigilantes wanna be cops.
And honestly, race has nothing to do with this. The race hustlers are trying to sell that this man was some sort of angel, be we all know that. However, his past doesn’t give McMichaels the right to execute him.
For example, the elder McMaster was a former cop and former investigator for the local District Attorney. Even in retirement, he may have had some sort of colorable law enforcement authority. Also, either or both of the McMasters might have been trained and credential as reserve deputies or members of the local sheriff's posse.
There may also be some obscure aspects of South Carolina law and yet unknown facts that suggest a rationale on which to stop and question Arbery. Due to the South's history as a predominantly rural and unsettled region, state and local law and practice tend to accommodate self-defense, self-help, and even some forms of vigilantism. Since the McMasters had a handgun stolen from a vehicle parked at their home, they were crime victims and may have stopped Arbery to ask if he had taken the gun.
Moreover, although the McMasters were armed, there is a right to openly long guns in South Carolina. Stopping Arbery while openly armed with a shotgun was provocative, but, without more, it did not in itself justify violence by Arbery. And, beyond question, Arbery was the aggressor and initiated physical violence, not the McMasters.
If that point is ignored, then all sorts of things can be used to justify attacking and killing another person. Until Arbery went after the McMasters, no one had suffered any physical injury. He was the aggressor, not the McMasters.