Given how folded those aluminum rims are, if these failures are real they appear to be the result of improperly heat treated aluminum, or aluminum that has not been heat treated at all (T0 condition, straight off the extruder). 6000 or 7000 series aluminum in the T6 condition will not deform anywhere near that much without cracking in my experience both fabricating with the metal and with bicycle rims.
Looking at the photos, you may be onto something here. That's a lot
of plastic deformation. Mavic rims are probably made from an alloy very much like 6061. In its usual, T6 condition, its elongation at failure is only 12%. In T0 condition, elongation is 25%, which is basically bubble gum for metals. But T0 is really, really weak.
I can't help wondering if Mavic built up some rims that had only been heat-treated to T4 condition with an elongation at failure of around 22%. It's a lot stronger than T0 (but weaker than T6) and that would explain how that rim folded sideways without breaking.
I also agree with people who suggest that this failure may be the result, not the cause, of the crash. Regardless of the heat treatment, that wheel took a large, abrupt side load. If the rim wasn't properly heat treated, a sideways skid that got caught suddenly (a high side, in motorcycle parlance) could definitely have caused that failure. Something
happened, and it really doesn't look like the spokes had much to do with it.
As many people here know, the bike industry has to deal with riders who experience JRA failures. JRA stands for "just riding along," which is what the rider was always
doing immediately before the part failed. The term is also a useful reminder that forks don't randomly bend backwards and wheels don't randomly fold over. The proximate cause is almost always something physical that happened at the time of failure or shortly before.
I don't mean to say the poor rider who crashed is lying. I'm just saying that when you're taken by surprise, it can be hard to determine whether your bike slewed to one side because your wheel bent or whether your wheel bent because your bike slewed to one side.
Diagnosing failure over the internet is always dangerous, but that wheel looks like it had stopped turning when it bent. It may have been too easily (wrong heat treatment) and it may legitimately not have been the rider's fault.
If Mavic had a run of mis-heat-treated wheels, they'd probably know about it. That's a big mistake. You can check the heat treatment of 6061 by measuring thermal conductivity. 6061-T0 has a higher thermal conductivity (184 W/m^2/K) than 6061-T6 (167 W/m^2/K) or 6061-T4 (154 W/m^2/K).