Its never anyones own fault.
Right, in this case, it's everyone BUT the dumbass who left his sister in a fucking locked car with the windows up in the heat.
Although it's dumb ass fuck to not be able to get out of a car thats locked, it's even dumber to leave a kid in a car in the sweltering heat with the windows up. The kid could have died in her sleep from heat stroke, that shit is serious business... when I was in the military Heat Exhaustion/Heat Stroke was one of their primary concerns, they actually have cards telling them how long they can torture us in certain heat levels, and how much water we need to inject every so often for different levels of heat/exertion... if she was passed the fuck out and dehydrated, it wouldn't surprise me if she died in her sleep. Which is NOT BMW's fault at all.
I feel like a lot of people really don't understand how US courts work, they get involved in the emotion of the situation and say "Well they HAVE to find them guilty, thats just WRONG!"
Unfortunatley, thats not at all how our court system works. They have to probe, beyond a shadow of a doubt, that that exact feature caused her death, and moreover, that there was no warnings, cautions, or notices ANYWHERE in the material the car came with. If there was, sorry customer, your dumbass fault for not reading the manual and understanding exactly how that piece of machinery operates.
Regardless of right or wrong, thats how it is.
Thats why when you buy stuff, there is a 40 page disclaimer of how not to use it, so if you electrocute yourself by trying to blow dry your hair in the bathtub, it's not the companies fault.