Hi Mike,
This is a interesting issue. Reproducing the problem here, i got a crash rendering frame 839 (non ortho)... but even converting RC to an editable mesh ! . It seems a bug of the scanline renderer, by some reason it crashes (or in your case it fails using ortho) with that specific geometry and view.
A very rare bug, but it would happen with a certain combination of numbers in the internal render algorithm. May be caused by a vertex, a face or whatever else... really it is impossible to know. I tried to render this frame using Mental Ray, and as expected, it doesn't show this problem.
Anyway, just moving the camera a bit seems to solve the problem.