Nathan it has happened before to RB and other manufacturers, but my rotors looked in great condition
So after I sent RB, as much info and photos as I could and offered to send higher resolution photos if required
This is an excerpt from Racingbrakes response
"To assure driving safety, track racing should not be rely on "track miles" or number of events, rather it's the driver's responsibility to have the brake inspected "prior" and "after" each event, and periodic replacement on pad and disc is recommended before a potential brake failure can occur"
I replied with
The info I provided, total miles, total track time etc
The photos are (worth a thousand words) of, Ring condition and thickness, pad condition, Hat temperature and failure areas etc
The links to my build threads was to show you how anal, I am with my cars maintenance and performance .
All the above was provided to you to help analyze what went wrong. With the idea that I would receive a logical explanation as to why this happened and some reassurance going forward that it was safe to use your produce again.
The best response I got was from a M3Cutters member Iain,
His comment was that I had put approx 35 trackday heat cycles through the rotors, which I hadn't thought of.
I worked out that I have done 7 trackdays, approx 5 sessions a day, so between 745-600 km.