But it is a big issue of human nature. If there are marked out lanes and I am in my lane, then the default behaviour is that I shouldn't have to worry about you in your lane, unless you wish to change lanes. As
@Milkfloat indicated - whenever there are "marked" cycle lanes (you know the ones - that white line a foot and a half from the edge of the road) drivers will consider that you have a safe zone and that they don't need to pass in the same way as they would if there were no line.
In this case the HGV driver is within his lines - he is as wide as the lines in fact, and therefore does not consider the vehicles in other lanes, cars, bikes or otherwise. Yes, the cyclists could have moved over and been more considerate, he could also have waited, but the lines are guiding behaviour IMHO.