Isovist outputting non-planar points

Quick question...

I'm having a problem with the Isovist component not providing co-planar points.  Only a few points out of 600 aren't in the same plane and it's by only a small fraction that they are off.  It seems that if Isovist arrays vectors around a center point on a specified plane that all the output points would be on the same plane.  What am I missing here?  Is it a rounding issue?  This seems to only be an issue occasionally because sometimes I can get it to work flawlessly with variations of the obstruction geometry.

Further, if I have to deal with this condition, what would be a quick way to make all the points planar, other than deconstructing and reconstructing the points with a common Y-axis coordinate.  I'm working with multiple paths at the same time, if I had to do this process I would also have to find and cull the specific branch that the issue occurs for each iteration of my model.

Thanks in advance.