I don't think that's at all fair, I've pointed to some of the various things that might have combined to cause this tragic event - to apportion blame we must wait for a professional investigation. The insurance company will certainly want to know as well as the maritime authorities

The whole point of a swing keel is to reduce the vessels draught in harbour or at anchor, but provide stability when sailing. It wouldn't be normal to have the keel down at anchor - it would be liable to significant damage if it hit the bottom. and even put the vessel at risk. But we don't as yet know - I merely mentioned this matter as one of the factors that might have contributed. The event happened at night and the squall/water spout or whatever wouldn't have been seen. If there is blame, then not securing hatches, portholes and companionways etc when there was a forecast for local storms (and there was, apparently) and maybe ensuring an enhanced night deck watch in case of trouble would be the captain's or mate's responsibility . We may learn that the design of the deck superstructure was not adequately strong in the case of a knockdown, the designer may have assumed this would never happen, eg the huge extent of large glass windows around a massive stern lounge seems an obvious vulnerability.

To my way of thinking a boat like this should never have foundered as rapidly in this way, even if the squall/waterspout was particularly severe, , and I suspect mostly due to the design (and this will apply to many other modern super-yachts) which made assumptions about seaworthiness and the robustness of modern materials and engineering that that at the extreme, as unfortunately happened here, were not sound. As regard to the captain, yes he shouldn't have lost the vessel, but as I say, best wait......