Nobody disputes that he entered to steal. So? As has already been pointed out, he doesn't have to be innocent to make killing him unlawful.
I'm not disputing that shooting a trespasser could be unlawful in a case of entrapment.
My argument is with the tone of the stories surrounding this case, as if the student was an innocent victim. It's a shame that he decided to sneak into someone's house. But, unless someone else tricked him into going into that garage, he wasn't an innocent victim. He'd entered a stranger's home with obvious criminal intent.
That's why this case is questionable to a certain degree.