I'm a fan of the DW but you can't ignore the fact that it has to be a wierd situation to be lapped/lap that car with it's shape. You throw a quick look in the mirror in a already stressed situation and try to judge exactly where the front is, then use all the track you can, then bang that front is just there.
But that flip was bad luck but inevitable, GTC car hit it on it's left rear quarter panel which put it sideways, on top of a hill and with that shape of the car it was bound to happen.