The rule of thumb with broken metal is: does one see discoloration ie is the surface of brake lighter in colour than the bare metal then it was excess force. If there is no discoloration or very little it is a material flaw. You have both. But arguably very much a warranty case. It s one of the things I brake yearly. Cranks.

 your commute must be gnarly!

 Haha, not even a kerb! Just sheared off as I pulled out at a roundabout.