That's totally part of the hub, Brian. And exactly because the hub cracked at the lockring threads, I would say that "operator error" has very little to do with it, and hub quality was crucial. The only thing that "operator" could have done better, was to remove the lockring and cog, put Loctite on the cog threads, rotafixa the cog onto the hub, and replace the lockring. All that, however, would have amounted to nothing if the hub material is weak, as it seems the case judging from the pictures.