Factor,
Based upon the pictures of the connecting rod big and small ends, I would suggest a failure of the oil circuit to get oil pumped through the crank and out of the crank pin onto the big end bearing and of the spray circuit to spray on the oil hole drilled in the small end of the rod. See page 53 of the owners manual for the oil circuit.
This could be caused by several things.
Absence of or failure of the small oil seal in the left side case cover for the end of the crank shaft could cause the damage to both ends of the connecting rod and the balancer..
Installing the connecting rod backwards would put the rod small end oil hole on the wrong side of the engine so the spray would not direct on the hole.
Plugging of the oil pump circuit.
Improper alignment of the crank pin oil feed hole relative to the crank cheek oil drilling.
Regards,
Joe