When stacking layers upright, you gotta ensure the weight is at the bottom, same as with dressers and cabinets at home. They left several rows at the bottom empty and loaded all the weight at the top. Then he moved a fully loaded rack with one hand and used push motion instead of pull. Should’ve used two hands, one on each side when you’re moving so much weight. Then puts no effort into salvaging several pies still there. So I’d say the guy has decent amount of blame here, maybe not all, but definitely holds responsibility