i've driven 7 and a half tonne lorries and tractors and unless you have the perspective from that height and distance, its difficult to appreciate how difficult it is to see cyclists when they're right inside you. so my advice is always always always keep away from lorries at LH turns. yes, it might mean you slowing your progress slightly but it's the safest thing to do. of course, some drivers are complete idiots and cut cyclists up. but as well as cycling assertively, you need to sometimes cycle cautiously. just like lorries should give cyclists plenty of room when passing them or manouevering around them.
whatever happened, its an awful occurence. very sad indeed.