Not so mad, if you look at
yesterday's discussion of the same issue, one of the suspension uprights failed as soon as Buemi hit the brakes. I think there is around 6g of braking force in those cars, so a lot of extra load is transferred to the front uprights in a very short space of time.
Obviously, they are designed to take that force but I doubt they'd be designed strong enough to take double that force so, when the right hand upright went, everything suddenly got put through the left hand upright, which instantly failed.