"were the 0ev shots really over exposed in raw or from the histogram and jpg"
Stan. I use the "highlight warning" and even with my D7100 (and even the D800)find a tendency to blow highlights. I can understand what you are asking, however when I have the highlights warning (0 EV)showing in the back screen and transfer it to Lightroom or Photoshop the highlights are overexposed in the way I see them on the camera screen. Perhaps not so severely, but still very apparent.
I did some testing at a wedding last week with the brides dress and took images at 0EV and then varying minus value EV's until the blown highlights disappeared. When I transferred the images the blown highlight images were seen on the RAW processor screen at varying severity until I arrived at the images taken with sufficient -EV to eradicate them. The -0.3 to -0.7 images were perfect.
The same thing happens when taking Egrets, Swans and white skies. As I never use jpeg, I wouldn't know if the same thing happens or not.