D5100 +50mm1.4G has weird line artifac

Hi guys, I have a weird 'issue' at my brandnew D5100. I hope you guys can see the pink line on her hand to her face. Does anyone know what is that line? I upload the picture straight from the memory card, there was no processing at all. (check the original size)

any one can explain, please?
seems like the line is dividing the highlight area to the shadow area.

The situation is she was about 4 feet from a lcd tv watching movie. I was using AutoWB with 1000 ISO. F1.8. Firmware v 1.00

I hope this is a fixable error. please help.

(sorry for my broken english)