Uniform Saturation - parade vs 3d scope

In the rgb parade, i always try to clean up my plus 100's and my sub zero trace. This is how i normally deal with color balance.
Last night i ran into a lot of strange 3d scope to rgb parade irregularities.

On one shot the RGB trace what with range but the 3d scope had trace well pass YUV compliance.
Another strange thing is that the trace formed a perfect circle nearly. Yet the content of the shoot was relatively the same and 5 other shots in the project, and they had nothing at all like a circle pattern.

How does the rgb parade ( rgb being inside of YUV) translate to the YUV 3d scope as it reads a script? -

Is the trace that registers at 100 or 0 on the rgb parade the same value as the trace that shoots out to the color brackets on the 3d scope?

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"