As far as I can see, we don't even know this was a blind spot incident, although that is probably our first reaction, based on what we all know about mixing big lorries and bikes.
I can certainly say, I've seen people on bikes riding in a way that I would have said they were very much to blame if they'd got squished. Cyclists are capable of 'careless' and 'negligent', like everyone else.
Obviously, I've also seen people drive recklessly. I do also believe that 'accidents' can happen. They shouldn't, in an ideal world, but we don't live in one of those. Yes, maybe if the lorry had had more mirrors (and we don't know how many it didi have), the incident might have been averted, but we also don't know that yet...