The nearside and offside mirrors cover the side of the vehicle,the blindspots could be lower than the bottom of the door,if its a high vehicle,This cement vehicle is fixed as far as i understand,so the driver,if unaware of whats there when he pulls up,can check by sitting up in his cab for any blindspot,so making them not blindspots,or even sliding about in his cab.It doesnt matter what is next to him,he can see it if he makes an effort to try.Doing these checks can be affected by a number of things,being in a hurry for what ever reason,seems to be the main reason these days,to make people take short cuts in what they do.Could this be classed as dangerous driving?Yes i think it should,because we still need to see if anyone or anything is in the way of a manouver.Ultimately the driver is responsible for the results of his actions in his vehicle,Im sure he will be feeling terrible about what has happened,because he should have checked properly before moving off.