Originally Posted by Clipped_in

They are good stems. I have two of them with never a problem. I have no idea what caused your failure. You should notify the manufacturer.
As far as recommendations, I have taken a real liking to the Zipp Service Course SL stems (also bars and seatposts). The Cobras have been lying around in the garage for a while.

Glad the outcome wasn't any worse. Wow!