I have never found the broken chain to see where it was broken.
My trouble with the chain breaker is when I am trying to put a new chain back on and I need to shorten the DiD chain to fit the length I want. The longer push pin keeps breaking and then it is not long enough to push the pin out to disconnect the links to shorten it.
Also, What is the average life of chain? How many hours or races should a chain last before changing.