I think that unless everyone that voted "Biker hasn't learnt defensive riding" did not vote as a result of his or her own accident that result is meaningless as there is no way you can say that about another person unless he told you so.
I think the answer to you question is SHIT HAPPENS 
I dont think any amount of defensive riding could of prevented my accident, I was just in the wrong place at the wrong time. I could of had the very same accident in a cage possibly with different results, but thats just my case. Shit does happen I've accepted it and will ride again..