Lastly they deserve credit for jumping on the problem fairly quickly, though I still wonder how this issue managed to slip thru quality control.
This may not have slipped through Quality Control. In big business Production always has the last word on whether or not the product gets shipped.
Were there any reports of det./pinging in any of the magazine articles? How about all of the test drives in California where the highest octane is 91? Do you think the STi's had something other than 91 in them for the test?
Quality Control can only report the issues. They can interrupt production to down machinery for repairs, but there isn't any further power in the department concerning production.