Engineering and construction are related but not the same thing. That video shows shoddy material and construction practices, it says nothing about the engineering behind the structures. A bridge collapsing because the load was incorrectly calculated is the fault of the engineer. But if it's because the contractor used too much sand in the concrete to cut costs then that has nothing to do with the engineering. You know those brick walls that were crumbling in the video? Too much sand in the mortar.