i think its a wind up, those forgings are stronger than strong things but the broken area looks like its been deliberatley busted
put it another way, if there so much of an upset to snap the ends from these forgings there would be evidence of damage at the other end due to pivot action around the large centre bore
i await the abuse from experts
gs
No abuse since it's a logical "what if" postulation
Possible answer is that the overload was so minimal as to not visibly upset the metal (to a mark 5 eyeball of a low resolution photo) pure fatigue looks that way)