2010 EC 300 Water pump shaft snapped & bearing collapsed

[justsam]

Half way through an Enduro yesterday I crashed whilst flat out up a gnarly hill. The bike fell gently on its right and immediately started rattling/knocking. I presumed it had moved the front pipe but it was not that and something terminal. End of my effort at the Dogs of WOR
On inspection I removed the right side engine and found the the water pump shaft snapped and the bearing in the crankcase totally collapsed, even the outer shell of the bearing was hanging out! So not as terminal as thought but still abit of a mess. Should be a reasonably inexpensive and easy fix.
My concern is why or how has this happened as I presume there's minimal load on this drive? Are they prone? Could the bearing of collapsed causing the shaft to snap?...
Any experience shared would be really appreciated