Mistakes and defects happen; anyone should know this, especially a mechanic!
He is willing to fix the problem with a new set of rotors, get off your high horse and accept the fact that crap happens and yes, people sometimes get inconvenienced...
In my business we buy the best products and pay more for them, but guess what, we still have defects. You can't produce thousands-->millions of parts/products and have them all be perfect.
BTW, I have a set of rotors from AuToMaX 95 and I have had them for years with zero problems.