"Either they have deliberately lost money for their own shareholders by doing what they did or they knew they were covered by another company for any loses"
Or maybe the board of CDU told them many things about the plans for the future which all turned out to be bullshyt? As a result they realised that cutting their losses immediately is their best way of managing their investment? Maybe they realised that the project economics are not what they expected? Maybe they were promised a DFS? Maybe they were told that sales would commence two years ago? Maybe dividends were promised for last year?
A lot of maybes but I guess that this is perfectly normal for CDU. Maybe one day we will find out why the conrnerstone investor dumped their shares? Maybe one day the company will sell something? Maybe one day they will operate in an open and transparent manner? Maybe.