In an email Apple support has confirmed that side-lit phones taken by the iPhone 5 will invariable have a Purple haze, saying this was normal behaviour for the device.
Our engineering team just gave me this information and we recommend that you angle the camera away from the bright light source when taking pictures. The purple flare in the image provided is considered normal behavior for iPhone 5’s camera. If you wish to reach me regarding this case number *********, please contact me at 1-877-***-**** ext. *******. I currently work Thursday-Monday: 7:00am – 3:30pm Mountain Time. If you reach my voicemail, please leave your name, phone number, case number and the best time to reach you. Email is ***********@apple.com.
With the acknowledgement that the issue is really a systematic defect with the phone, Apple has quietly given up the crown of the best smartphone camera regular consumers can buy, a mantle I am sure Nokia is all to willing to to pick up in 4 weeks time.