Note that this wasn't a case of the money being lost because the key was lost when the owner died as per the initial headlines - in this case the money simply wasn't there in the first place: "Quadriga likely never invested the funds entrusted to it, according to Chainalysis, ... Either the funds were never received or quickly went missing" and "Ernst & Young found five Quadriga cold wallet addresses, but they were empty, containing no cryptocurrency since April 2018."[0]

[0] https://en.wikipedia.org/wiki/Quadriga_Fintech_Solutions