The way I read the article it appears he was not. Scott shot at the car that was threatening him and hit the other car, killing Niles. Now, did the bullet go through the car full of people threatening him and then hit Niles? In that case I could see him not being charged. It was just unfortunate that the bullet didn't hit one of the perpetrators first.
Okay, fact gained. Mr. Niles was not in the car with the girls.