I'm with Pops on this one regarding the possibility of hydrogen embrittlement. Though Gilbertson did a reasonably thorough description, he failed to mention anything about the plating process, perhaps he's unaware of the potential problems.

I'd love to see the end grain of the break to see if there is any discoloration to indicate a fracture that was undetected before the failure, or if it were consistent in color indicating a sudden, catastrophic failure. Based on the discription from Gilbertson it sounds a lot like what could happen with hydrogen embrittlement, especially considering how few miles/time of use his discription implies.