Never seen it, but a bit of metallurgical background can help. Cast iron is very hard, but brittle. Hit the handle with a hammer, and it will come off. Drop it on concrete, and it may snap off. Steel competition kettlebells, however, don't share this characteristic. Hit the handle with a sledgehammer, and the kettlebell will go flying across the room. It might bend or dent, but it won't break.
I dropped a cast iron 16k on my concrete garage floor once. It landed on the ball, and there is a dent in the floor. The handle is fine.
Under normal use on a soft surface, it's not likely.