Both of them could have easily avoided the incident so I dont see how that becomes a criteria for determining fault.
Sure, Webber could have avoided it by not competing, but he did compete and did so with an exceptional piece of driving. He was holding his line very comfortably, and Hamilton turned in on him.
Hamilton could have avoided it by driving better, giving Webber a few more inches and he would have come out ahead anyway.
So what would you prefer, not competing or better driving?
As for describing Webber as always letting the red mist get the better of him, I have no idea where that comes from, especially when you look at the track record of three of the four drivers he is competing with this year, compared to them the guy is a saint.