What caused this damage

Is it an illusion or is the pic of the small end of the rod slightly discolored from heat? Have you lookied at the wristpin and small end bore to see if it might have been too tight? The other pics indicate pressed pins so the color could be from installation? But still, have you looked at the wristpin bores in the piston? Just curious. Have you decided you found the actual problem that caused the failure? dan...