The sapphire Apple is using is artificially made in labs, and come out crystal clear. Natural sapphire can be blue, but that's not what Apple uses in their cameras. So that couldn't be the cause of the purple. Especially after their edit saying that the same issue is found with the 4S.
The tv show How Its Made or How Do They Do That (I forget which one) on the Science channel shows exactly how artificial sapphire is made. Is the same type of sapphire used as windshields on military attack helicopters.
I'm so glad that MR is choosing not to report this as news b/c it most certainly isn't. Everyone wants a piece of the 24/7 media pie, and the "inevitable downfall of Apple" sure generates page views & ad hits.
Another issue with the iPhone 5? They just keep on finding things wrong with this phone lol. Congrats to the millions of field and beta testers out there that lined up to get this thing. It's getting obvious Apple skipped that part.