it is very difficult to establish cause and effect here; did something funny happen and cause a prang that bent the wheel, or did the wheel start to collapse for some reason and did that cause the accident?
I've seen a lot of pranged wheels and they very often bend at a pinned joint during the wheel failure. I have never seen a wheel that failed 'because of the pinned joint'.
However the wheel may be the culprit in this case. The latest mavic CXP rims are made in Romania. They look like the older CXP 22 rims but they are not the same. They have heavily machined braking surfaces (which are piss-thin just like all the other mavic rims are these days) and are slightly lighter. Some old model CXP22s had thick braking surfaces and an external wear indicator. These rims last for ages, if they don't crack first...
All wheels are (in theory) vulnerable to a self-pringling failure mode. It is really a sort of Euler buckling; an elastically initiated instability that, during failure, may become plastic (i.e. permanent). If you read a good wheelbuilding book (Like Brandts) it will explain this in more detail. Most modern rims are not as vulnerable to this kind of failure as they used to be; when Brandt wrote his book most rims were. He used the onset of self-pringling as a proxy for setting maximum spoke tension. There is a whole generation of folk who build wheels that have never seen this happen. Current CXP rims (and other similar) can self-pringle.
Things that make this likely to happen include
- a rim that isn't very stiff
- a rim that isn't very strong
- a wheel that has uneven tensions
- a wheel that has very high tensions
- a wheel that is heavily dished
- a wheel that has narrow-spaced flanges
- a wheel that sees a lateral force
It is impossible to say what happened exactly, but I will note that some wheelbuilders refuse to build certain rims onto hubs that are built like that, with narrow spaced flanges, because when the spoke tensions are as high as they like them to be, the wheel is on the verge of euler buckling.
Hope you are healing OK.
cheers