Since this appears to be a perennial discussion of debate, I just want to add that:
a) It seems absurd to condemn such sensible discussion of accident cause such as this and, if everyone will forgive me, rather sanctimonious.
b) I too don't like these condolences threads which in the absence of direct knowledge of the people involved seem pointless and, again, rather sanctimonious. If I ever pile in, God forbid, please don't start one for me. (And if you knew me personally you probably wouldn't!)
Well done to BRL for separating the threads.
The Curmudgeon