If it really happened according to the article, there was an altercation in the restroom, then later it restarted at the food court with the attacker bringing a friend. If that is what is determined to be the truth, then I'd say it was justified. If they prove that the altercation never ended, but just started in the bathroom but then extended itself to the food court. then they may say that the shooter had opportunities to end the fight before the gun was pulled and it will be more difficult to be exonerated.