Thought i'd run the file through http://validator.w3.org ... and it validates.
That makes it less likely an Inkscape related problem, i guess.
Back to reading code ...

So the error occurs when the importer generates the geometry inside blender. (That is, after parsing, which seems to work fine)
Inside class SVGGeometryPATH an object (curve) is created, a bezier spline is added to it, then the script starts adding bezier points, copying over the coordinates from the parsed data.
When printing the spline's bezier_points array length it becomes apparent that the error occurs right when an overflow happens:

len(act_spline.bezier_points)

...

32764
32765
32766
32767 (= signed 16 bit int range upper border)
-32768 (= signed 16 bit int range lower border)

So now the question is: Is this by design?

If Blender internally only allows splines with a maximum of 32767 points - and intentionally so - then this is not really a bug of the importer, but rather a shortcoming in gracefully handling this case and reporting that Blender does not support curves with that many points. If on the other hand, we would actually want Blender to be able to handle such an amount of spline data, we probably have to dig deeper and fix how (or in other words: with which type) the bezier points are allocated internally.

I hope my assessment of the situation is correct and I didn't overlook something else.
In any case, I would now need feedback to continue. TIA :)

Here's two little python snippets for triggering the issue directly from the console:

Create Curve (= 2 points) and add 32765 points = 32767 points - works

bpy.ops.curve.primitive_bezier_curve_add()
bpy.data.objects['BezierCurve'].data.splines[0].bezier_points.add(count=32765)

Create Curve (= 2 points) and add 32766 points = 32768 points - crashes

bpy.ops.curve.primitive_bezier_curve_add()
bpy.data.objects['BezierCurve'].data.splines[0].bezier_points.add(count=32766)

It seems reasonable to me to bump some members in the curve data structures like pntsu from short to int, since this seems quite low. But you'd need to carefully check all the files where such member variables are used, since they may still be assigned to shorts in some computations.