I use a D700 with leica r lenses, and do get purple fringing and ca in certain cases. Also before buying the D700 i had a D3 with the nikon 24-70 2.8 zoom to test, and in a particular occasion made a picture of tree backlit by early morning sun, shot wide open at 28mm. It shows heavy purple finging and ca.Of course. Or a really poor sensor design, or a really poor lens design. At the end of the day, it could be any of these, but for Leica's sake, we hope it's just a conversion software issue -- and IMO that is the likeliest issue. (Phase files can have excessive fringing too if you convert them in LR...)
Minute apart i made a picture with my M6 and elmarit 28mm 2.8, wide open, and kodak portreta negative film. Also purple fringing and some ca, but less.
With my D700 and leica glass, i get in extreme backlit cases ( or strong sun reflections) purple fringing, like sun reflecting via small waves on water surface. I use lightroom for my raw conversion and development.
I took these issues as a given based on extreme light conditions. With this thread i am getting more interested, and plan to look at those raws (and scan's) again and see if other developers like C1 and NX2 do a better job on this particular issue.
Note that in the nikon D3/24-70 images, i find CA issues present much stronger that in the case of leica glass.
P.S.: in one case, still under investigation, it looks like it is the LCD monitor i use (EIZO), with dark and strongly saturated blue/purple color, it appears the LCD monitor is causing what looks like CA.
To summarise, despite the D700 filters in front of its sensor there are issues, purple fringing does also occur when using film. So if a particular body(electronics,firmware)/lens/raw developer does not show these issues, it would be very interesting to find out why!