Houdini writes the following string into RIB when it generates the DeepShadow:
Display “+./3d/renderData/shadows/shadow.dsh” “deepshad” “deepopacity” “volumeinterpretation” “discrete”
That's why the 64 bit PRMan is crashes.
Right string should be
Display “+./3d/renderData/shadows/shadow.dsh” “deepshad” “deepopacity” “string volumeinterpretation” “discrete”
The difference in the “string” word. The type of parameter should be described.

I've just tried and looks like I have the same problem here, on 8.2.30 32bit and prman 13.0.4 64bit.
I found that prman crashes when I have both that string and complex subdivision model in RIB - on simple polygons it's work =\
But anyway, if I generate rib file first and fix all “volumeinterpretation” strings to “string volumeinterpretation”, it starts to work perfectly in all cases.

I think houdini violates RIB syntax rules here, because it declares custom variable of unknown type. But I'll ask Pixar support about that strange behavior anyway - segfault isn't the best way to say you have error in RIB