Kamiya would never bad-mouth Microsoft, no matter what. First and foremost it'd be bad business going forward, it'd make nobody look good, and in the end both Platinum and MS already took the L on the endeavor, so there'd be no upside to it. This was an outcome that neither side would have wanted.
The fact of the matter is that only the people on the "inside" know precisely what went wrong, and although I'm pretty sure that everyone involved has his/her own opinion on who made the most egregious mistakes, broadcasting those views to the world would serve no purpose.
Kamiya taking a pragmatic, dignified, stance on the matter publicly, whilst focusing his energy on re-building team confidence and unity strikes me as excellent leadership.