I still struggle to understand how a big issue like this wasn't picked up by Porsche during testing , I could understand Ferrari or Lamborghini as is my believe they don't do extensive durability testing as other "lesser" OEM's but Porsche?! The new GT3 engine is longer the Metzger engine but an upgraded version of the current direct injection flat-6 you can find in other 991's, was this the reason this problem went under the radar? Porsche believing that the modifications did not require extensive testing and deadlines for launch? Or just plain unlucky? I'm sure we'll never know exactly and this will haunt the boys from Stuttgart for years to come and probably add to those automotive dogmas like the 996 engines. One thing's for sure with the "interweb" at least we're getting loads of details and insight on this issue, you can find loads and updated info on the Pistonheads site.
Also people seem to forget earlier on there was a fire with a 991 prototype in Germany back in 2011, according to the article that car was running an engine specific for the Chinese Market. Related?