It seems that the descent was controlled and therefore, frankly, it is not clear why the overturning was not prevented by stopping the descent procedure. It was immediately clear that «something had gone wrong». I saw a similar situation when I launched a 60m yacht at a famous Italian shipyard.
The tipping did not happen then, but the tilt reached 15 degrees.
It took a long time to figure out who was to blame and what to do. The shipyard went to the naval architects, the architects, in turn, went to the shipyard. And the mistake was in the wrong assessment of the weight of the ship, or rather, its distribution on the yacht. This, in turn, led to a shift in the vertical component of the center of gravity. The Americans, I think, had a similar problem.
When ordering a yacht do not forget the importance of weight control during construction, ask the shipyard to provide you with their procedure for checking the weight. There are different methods, but the easiest and most effective is to weigh the equipment and materials before they are installed on the boat with the appropriate tables filled out. The Dutch, for example, even measure the thickness of the sheet metal to within a hundredth of a millimetre to fix the exact weight. Well, I won't be tired of theory, it's a topic for a separate big article.