there was a thread on something similar to this on the porsche forums dealing with some HRE's with an after market paint job. The HRE's like these, were 3 piece and painted by a third party company. The guys at HRE explained it pretty well in the thread on how just slightly over heating a forged wheel can compromise the structural integrity much much more than a regular wheel. I wish I still had the link.
Anyways, HRE inspected his wheels and sold him a brand new set of wheels of his choice for an amazing discount.
The HRE's had small stress cracks and not a catastrophic failure like these which could be due to many reasons.