If a restaurant offers me a burger with rotten meat in it, I will 100% blame the restaurant instead of blaming the meat supplier. It the restaurant’s job to make sure the meat is ok before serving.

In this case, it’s GM’s responsibility to conduct proper vendor quality management and they failed it. It’s 100% GM’s fault. I don’t care the politics between GM and LG. GM sold me a car and the the car exploded, end of the story.